Citations
- 430 F. Supp. 2d 195
Full opinion text
DECISION AND ORDER
MARRERO, District Judge.
Plaintiffs Minerals Technologies Inc. (“MTI”) and Specialty Minerals Inc. (“SMI”) (collectively, “MTI”) brought the underlying action against defendants Omya AG, Omya Industries, Inc., and Omya, Inc. (collectively, “Omya”) alleging infringement and inducing infringement of two United States patents, No. 5,043,017, (the “ ’017 Patent”) and No. 5,156,719 (collectively the “Patents”), that are owned by MTI and based on essentially the same papermaking technology. By a Settlement Agreement (the “Agreement”) dated November 22, 2005, the parties settled a related action, resolved a number of other issues in dispute in the instant case, and thus narrowed the scope of this litigation. The Agreement calls upon the Court to provide interpretations of certain important terms used in the Patents and, on the basis of that construction, to resolve the remaining matters about which the parties still disagree. Set forth below are the Court’s findings, conclusions and reasoning in this regard.
I. FACTUAL BACKGROUND
The Patents relate to a chemical process for manufacturing paper. The technology uses calcium carbonate as a filler and coating substance that does not affect the acidity of paper when it is mixed with wood pulp during the process and that improves the quality of the product’s color, gloss and opacity. Normally, calcium carbonate, an alkaline substance, when mixed with wood pulp decreases the acidity of the mixture, which is referred to as a paper “furnish” or “slurry,” causing the filler to decompose. This change in acidity can be harmful for certain types of neutral or weakly acidic paper.
The ’017 Patent was issued in 1991 to June Passaretti (“Passaretti”) for a paper-making system based on the use of a calcium carbonate that is “acid-stabilized” in a neutral to mildly acidic environment of a mixture composed of a calcium-chelating agent and/or a conjugate base, combined with a requisite amount of “weak acid.” In this system the calcium carbonate does not affect the acidity of the slurry because the weak acid works to control the pH of the mixture and maintain it in equilibrium. Claim 1 of the patent asserts protection for:
An acid-stabilized finely divided calcium carbonate comprising a mixture of at least about 0.1 weight percent of a compound selected from the group consisting of a calcium-chelating agent and a conjugate base, together with at least about 0.1 weight percent of weak acid, with the balance to give 100 weight percent being finely divided calcium carbonate, such that the calcium carbonate is coated by and is in equilibrum [sic] with the calcium-chelating agent or conjugate base and the weak acid.
Id.
In the underlying action as filed, MTI sought relief against Omya, its primary competitor in the relevant market, on the grounds that Omya had infringed and induced paper manufacturers to infringe the Patents by conducting tests in which calcium carbonate and a calcium-chelating agent were combined with a weak acid used to reduce the alkalinity of the slurry and resulting paper product, and by evidencing Omya’s intentions to expand its papermaking business by means of this process. Specifically, MTI points to pa-permaking tests Omya conducted at a mill owned by a company named Stora Enso North America (“SENA” or “Stora Enso”) in December 2003 (the “2003 SENA Trial”) and August 2004 (the “2004 SENA Trial”) as instances in which Omya induced infringement of MTI’s patents by providing supplies and instructions for paper-making that used the same components in the requisite amounts to satisfy the “weak acid” requirement described in the Patents (the “Weak Acid Requirement”). The parties agree that at the 2004 SENA Trial, which was conducted over a seven-day period, Omya injected 36.5 tons of carbon dioxide (C02) into an aqueous paper furnish consisting of a calcium-chelating agent and 1034 tons of calcium carbonate filler.
It is also undisputed that some amount of the carbon dioxide reacted with the water in the furnish to produce some amount of carbonic acid (a weak acid). The quantity of carbonic acid thus formed at the trial was not measured. MTI argues that Omya’s use of carbon dioxide in this test met the Weak Acid Requirement in three ways: (1) by itself, on the ground that carbon dioxide is classified in the chemical literature and recognized by those skilled in the chemical arts as a “Lewis” acid that exhibits the properties of a weak acid and that was present in the requisite amount in the system; (2) through its formation of a requisite amount of carbonic acid; and (3) by the production of bicarbonate in a sufficient quantity from the further reaction and disassociation of carbonic acid in the slurry. According to MTI’s computations, the 36.5 tons of carbon dioxide used at the 2004 SENA Trial, in combination with 1034 tons of calcium carbonate, would have exceeded the 0.1 weight percent relationship of these substances in the mixture as claimed by the Patents. Similarly, MTI contends that the amount of carbonic acid and bicarbonate produced at the 2004 SENA Tidal each totaled 50.6 tons, or about 4.9 weight percent, thus exceeding the 0.1 limitation the Weak Acid Requirement specifies. MTI also maintains that Omya’s use of any of these three claimed weak acids at the 2004 SENA Trial infringed the Patents under the doctrine of equivalents.
Omya admits that it conducted the Stora Enso trials, but claims that for several reasons the tests did not infringe or induce infringement of the Patents, either literally or under the doctrine of equivalents. First, Omya asserts that carbon dioxide is a gas, not a “weak acid” within the meaning of the literal terms of the Patents, and that indeed by this standard it cannot be classified as an acid at all, whether under the Lewis acid definition claimed by MTI, or according to the “Bronsted” acid definition. Omya contends that the latter definition is more commonly known by those skilled in the chemical arts and is thus the understanding of “weak acid” that comports with the ordinary and customary meaning of the terms and teaching of the Patents. Second, Omya argues that at the 2004 SENA Trial it was not the carbon dioxide itself that performed the weak acid function to lower the alkalinity of the paper furnish, but the carbonic acid produced by the carbon dioxide, some portion of which reacted with the water when injected into the slurry. According to Omya’s analysis, the amount of carbonic acid produced totaled approximately 0.0129 weight percent of the calcium carbonate mixture, well below the 0.1 percent measure the Patents claim as a minimum. And third, Omya claims that the 2004 SENA Trial did not infringe because the calcium carbonate in the system was not “acid-stabilized.” Rather, the furnish was maintained at all times at a pH level of 7.2, thus in the alkaline range, rather than neutral or acidic, as the product would have to be if the Passaretti technology had been employed according to its literal terms.
II. ISSUES BEFORE THE COURT UNDER THE AGREEMENT
The issues remaining in dispute that the parties have asked the Court to resolve are set forth in Paragraph 4 of the Agreement. The first section of Paragraph 4 reads as follows:
Although the parties have agreed to settle the Antitrust and Patent Actions as set forth above, they continue to disagree as to the requirement in U.S. Patent No. 5,4043,017 (the “’017 Patent”) and U.S. Patent No. 5,516719 (the “ ’719 Patent”) that at least about 0.1 weight percent of weak acid be used (the “Weak Acid Requirement”); specifically, the parties disagree whether the Weak Acid Requirement was met in connection with the papermaking trial that took place at Stora Enso North America, in Duluth, Minnesota, in August 2004 (the “August SENA Trial”).
(Id.)
In an earlier ruling addressing a dispute concerning the scope of what the Agreement called upon the Court to resolve, the Court determined that this provision describes the parties’ continuing disagreement as to whether the Weak Acid Requirement was met by any means during the 2004 SENA Trial. See Minerals Tech. II, 406 F.Supp.2d at 335.
However, because Omya used carbon dioxide at the 2004 SENA Trial, the Agreement describes several additional aspects of the underlying dispute the parties asked the Court to review in connection with its determination of whether the Weak Acid Requirement was met during that experiment. There was no disagreement that Paragraph 4 placed before the Court the narrow question of whether the amount of carbonic acid formed at the 2004 SENA Trial satisfied the Weak Acid Requirement. (See id. at 335.) This section of the Agreement reads:
MTI contends that the amount of carbonic acid formed by the use of the C02 satisfied the Weak Acid Requirement. Omya denies that. The parties have agreed ... to resolve this issue before [the District Court].
(Agreement, at ¶ 4.)
The Court also concluded, however, that the remainder of Paragraph 4 enlarges the scope of what the parties request the Court to address. In particular, in addition to rendering a “definitive ruling” on the issue of whether the Weak Acid Requirement was satisfied at the 2004 SENA Trial, the Agreement calls for the Court to provide a detailed explanation concerning the chemical reaction of carbon dioxide in a paper furnish. Specifically, that second task requests that the Court “also” explain “the basis for its decision,” including three distinct components: (1) a “detailed statement” of “its claim construction of the term ‘weak acid’ as it relates to the formation of carbonic acid through the addition of C02 to a paper furnish,” “as well as” (2) an explanation regarding “the circumstances under which the addition of C02 to a paper furnish will meet the Weak Acid Requirement,” “as well as” (3) “the circumstances when carbonic acid, alone or in combination with other weak acids, meets the Weak Acid Requirement.” (Id.; see also, Minerals Tech. II, 406 F.Supp.2d at 338.)
The last sentence of Paragraph 4 spells out a third task for the Court that also arises as a component of the underlying question. It records that the parties continue to disagree with regard to “the proper application of the Doctrine of Equivalents, Prosecution Estoppel, and other legal issues as they relate to the Weak Acid Requirement,” and asks the Court to “address these issues as well,” to the extent they are raised by the parties. (Agreement ¶ 4.)
There is another provision of the Agreement that has some factual bearing on the Court’s resolution of the matters at hand. It is contained in Paragraph 7 and states that “for purposes of this Agreement ... both phosphoric acid and carbonic acid are weak acids,” and that “there is no intent by this Agreement to limit what would otherwise constitute ... a weak acid.” (Id. ¶ 7 (emphasis added).) Therefore, the Agreement does not rule out the prospect that carbon dioxide or bicarbonate could be found to constitute weak acids for purposes of the Weak Acid Requirement.
III. THE TRIAL
To address the parties’ remaining disputes as set forth in the Agreement the Court conducted a bench trial on December 19 and 20, 2005 and January 20, 2006. The evidence, issues and arguments at the trial are described below.
A. MTI’s CLAIMS
MTI argued at the trial, and in related documents entered into the record of these proceedings, that the Patents allow that various claimed weak acids, alone or in combination, could serve as the weak acid in the system. In particular, it contended that the Weak Acid Requirement was met at the 2004 SENA Trial both literally and under the doctrine of equivalents by the presence of requisite amounts of three different substances MTI claims are weak acids, as summarized above: carbon dioxide, carbonic acid and bicarbonate. According to MTI any one of these weak acids, or a combination of them, functioned during that test to attain the result of lowering and maintaining the pH of the slurry at a constant level of about 7.2, thereby achieving what the Patents describe as an acid-stabilized calcium carbonate coated by and in equilibrium with the other compounds in the system.
1. Carbon Dioxide
MTI presented the testimony and reports of its expert, Robert Pelton (“Pel-ton”), a chemist whose field of specialty and experience are grounded in the paper-making industry.
In support of its argument that carbon dioxide qualifies as a “weak acid” as the term is used in the Patents, MTI relied on several sources and forms of evidence. First, it pointed to statements made by Omya representatives during the course of this litigation purportedly acknowledging that carbon dioxide is commonly referred to as a weak acid with an assigned pKa value, a chemical measure by which the weakness of an acid is determined. (See Minerals Technologies Inc. and Specialty Minerals Inc.’s Post-Trial Memorandum dated February 3, 2006 (“MTI’s Posh-Trial Mem.”), at 4.) Second, MTI cited portions of a number of chemistry texts that refer to or describe carbon dioxide as a weak acid. (See id. at 5.) And third, MTI relied on the opinion of Pelton, who testified that carbon dioxide is a Lewis acid that qualifies as a weak acid for the purposes of the Patents. (See id.) In this connection, MTI points out that the Patents specifically list boric acid as a weak acid that could satisfy the Weak Acid Requirement and that, as conceded by Omya’s experts at trial, boric acid in an aqueous solution functions as a Lewis acid by bonding with a water molecule and then donating a proton. (See id. at 7.)
Alternatively, MTI contended that carbon dioxide may be classified as a weak acid under the doctrine of equivalents. On this point, MTI argued that in a paper furnish, carbon dioxide acts just as boric acid does to perform the same function of lowering pH: it dissolves, reacts with the water to form carbonic acid, a conceded a weak acid, which then donates protons to the furnish, and in turn disassociates to produce bicarbonate, another known weak acid. (See id. at 8.) Similarly, MTI maintained that carbon dioxide as used in the 2004 SENA Trial may also be determined the functional equivalent of phosphoric acid, which Omya employed at the 2003 SENA Trial to maintain the pH of the furnish at between 7.1 and 7.3. (See id. at 9.) Further, MTI argued that carbon dioxide is also the equivalent of carbonic acid, in that once hydrated it serves as the acid anhydride of carbonic acid, its conjugate acid.
There is no dispute that the 36.5 tons of carbon dioxide injected into the 1034 tons of calcium carbonate in the paper furnish at the 2004 SENA Trial constituted at least 0.1 weight percent of the calcium carbonate. Accordingly, were the Court to find that carbon dioxide properly may be termed a weak acid, MTI would have demonstrated that the literal terms of the Weak Acid Requirement were met at the 2004 SENA Trial by this means.
2. Carbonic Acid
As stated above, the parties agree that carbonic acid is a weak acid as the term is used in the Patents and that at the 2004 SENA Trial the carbon dioxide injected into the furnish dissolved and reacted with the water. Some or all of the dissolved carbon dioxide — -the precise amount remains in dispute' — converted to form an amount of carbonic acid, which functioned to control alkalinity, maintaining the pH of the slurry at about 7.2. For the purposes of the Agreement, the parties’ principal disagreement in this respect is whether the amount of carbonic acid produced during the test met the Weak Acid Requirement by exceeding the 0.1 weight percent limitation. On this point Pelton testified that at a pH of 7.2 in the slurry most or all of the 36.5 tons of carbon dioxide introduced into the paper furnish converted to form about 50.6 tons of carbonic acid, as a transitional state before further reacting to produce bicarbonate, each of these weak acids yielding a weight percent measure of 4.9 of the calcium carbonate in the system. (See id. at 10.)
According to Pelton, the carbon dioxide injected in the slurry dissolved and remained in the system. It continuously recycled and, through a relatively slow reaction by chemical standards, disassociated in the water to generate carbonic acid which, through further consumption of carbon dioxide, formed bicarbonate. Under this analysis of the system, because the carbon dioxide was constantly consumed by the paper furnish, carbonic acid was being produced continuously to generate bicarbonate, and thus, more of the carbon dioxide that was dissolved and recycling in the water was disassociating and converting to produce carbonic acid. (See id. at 14; Trial Tr. at 73.)
3. Bicarbonate
Citing Pelton’s calculations, MTI argued that the 36.5 tons of carbon dioxide used at the SENA August Trial, at a slurry pH of 7.2, formed 50.6 tons of bicarbonate, which translates into 4.9 weight percent of the calcium carbonate in the paper furnish, thus meeting the Weak Acid Requirement. Moreover, MTI maintained that the formation of bicarbonate satisfied the Weak Acid Requirement under the doctrine of equivalents, insofar as it is a weak acid and functioned as such at the 2004 SENA Trial, lowering the pH of the paper furnish by disassociating and generating hydronium ions and donating protons to the slurry.
B. OMYA’S RESPONSES
Omya counters that the evidence produced at the trial and related record of this proceeding was not sufficient to satisfy MTI’s burden to prove its claims by a preponderance of the evidence. In support of its defense, Omya relied on the testimony and reports of two experts, Michael Waller (“Waller”) and Christopher Cummins (“Cummins”). Omya contended that the well-established ordinary and customary meaning of the term “weak acid” to a person skilled in the chemical arts at the time the Patents were issued was what is known as a Bronsted-Lowry acid. (See Defendants’ Posh-Trial Memorandum of Law in CCyCarbonic Acid Mini-Trial, dated February 3, 2006 (“Def.’s Post-Trial Mem.”), at 4-5.) According to both Waller and Cummins, a person of ordinary skill in the chemical arts at that time would not have classified a Lewis acid within the definition of a weak acid. (See id.)
Omya then argued that carbon dioxide is not an acid under any definition of the term, and thus cannot be considered either a weak acid or a Bronsted acid because carbon dioxide (1) does not possess a proton to donate; (2) does not disassociate and release a hydronium ion when reacting in an aqueous solution; and (3) does not have an assigned value on the pKa scale, which is used to measure the strength of Bronsted acids, because it has no protons to donate in reacting with water. (See id. at 6.)
Omya dismissed MTI’s argument that carbon dioxide is a Lewis acid as irrelevant because: (1) by definition, a weak acid encompasses only Bronsted acids; (2) there are many Lewis acids that cannot be considered weak acids; (3) Lewis acids are characterized as “hard” or “soft,” unlike Bronsted acids that are termed “weak” or “strong”; and (4) in any event, carbon dioxide is not electron-deficient and thus cannot properly be considered a Lewis acid under the accepted Lewis acid definition as “an electron-deficient molecule that can act as an electron pair acceptor.” (Id. at 6-8.) For this reason, Omya asserts that the classification of carbon dioxide as a Lewis acid in the chemistry textbooks cited by MTI is incorrect.
Omya next rejected MTI’s claim that the Patents were also infringed by application of the doctrine of equivalents. First, it argued that MTI’s invocation of the doctrine of equivalents is vitiated under the related doctrine of prosecution history es-toppel because in processing its application to obtain the Patents, MTI made statements asserting that the word “weak” with regard to “weak acid” was well known to those skilled in the chemical acts and that the terms have a well-established meaning in that context. Omya thus contended that because at the time the Patents were issued the recognized meaning of the term “weak acid” to persons skilled in the chemical arts was a weak Bronsted acid, or proton donator, MTI should be estopped from now claiming that a “weak acid” means anything else, in particular a Lewis acid. (See id. at 11.)
Moreover, Omya maintained that the carbon dioxide used at the 2004 SENA Trial was not the equivalent of a weak acid because when injected into the paper furnish most of It did not disassociate to convert into carbonic acid, and therefore the unconverted carbon dioxide gas itself (1) did not function as an acid, (2) had no effect on the acid stability of the calcium carbonate, and (3) did not otherwise operate to lower the pH of the slurry to the alkaline pH of 7.2, contrary to the function of the weak acid as described in the Patents, which teach that the calcium carbonate is stabilized in a mildly acidic environment. (See id. at 12-14.)
Finally, though it acknowledged that carbonic acid constitutes a weak acid within the meaning of the Patents, and that at the 2004 SENA Trial it was the carbonic acid, and not the carbon dioxide, that functioned as a weak acid to lower the pH of the paper furnish, Omya nonetheless contended that the amount of carbonic acid formed during the test was less than 0.1 weight percent of the calcium carbonate in the slurry. (See id. at 14-15.) Specifically, Waller testified that according to his computation, the 36.5 tons of carbon dioxide injected into the furnish containing 1034 tons of calcium carbonate yielded carbonic acid in an amount of approximately .0129 weight percent in relation to the calcium carbonate present, thus less than the Patents’ 0.1 weight percent limitation. (See id. at 16-17.) Relying on Waller’s testimony, Omya asserted that all of the carbon dioxide injected into the furnish dissolved and was then pumped to a decu-lator which, according to Omya, operated to remove all dissolved gases from the furnish to prevent holes and other defects in the paper product. (See id. at 16.) By Omya’s theory, the small portion of dissolved carbon dioxide not removed by the deculator reacted with the water in the furnish to form some carbonic acid, and thus, because of the rapid speed at which the slurry moved through the Stora Enso papermaking machine, was not available to form any more carbonic acid. (See id.)
In response to Pelton’s analysis calculating the amount of carbonic acid yielded by the 2004 SENA Trial as 4.9 weight percent, Omya challenged the conclusion that all of the carbon dioxide used at the trial remained in the system and was consumed while producing carbonic acid and bicarbonate. On this point Omya asserted that Pelton did not consider the “rate constant” of carbon dioxide nor the time the furnish took to travel from the point of injection of the carbon dioxide to the deculator, where the dissolved unconverted carbon dioxide, according to Omya’s argument, was all removed from the slurry. (See id. at 18.) Omya rejected Pelton’s analysis on the ground that it posited a “closed system” that assumed the presence of an infinite amount of carbon dioxide for an infinite time. (See id. at 19.)
Finally, Omya contended that Pelton’s theory that the carbon dioxide used in the paper furnish at the 2004 SENA Trial continuously produced carbonic acid until it was all consumed by the bicarbonate, despite the presence of a calcium-chelating agent, is inconsistent with the premise of the Patents, which teach that when the calcium-chelating agent is applied to the surface of the calcium carbonate, it acts to reduce the solubility of the calcium carbonate’s surface and thus to prevent the acid from reacting with the surface of the filler. (See id. at 21.)
III. DISCUSSION
A. TESTIMONY OF EXPERTS
Resolution of a complex dispute laden with disagreements over highly technical and scientific issues, as are the questions the parties have placed before the Court, necessarily rests in substantial part on which of the experts the Court considers more persuasive overall and better qualified to address the specific matters in contention, as well as what arguments, analysis and authority offered in support of their opinions the Court finds more compelling. Here, each of the experts who appeared at trial and submitted reports had impressive professional credentials. The Court found each of them sufficiently learned and distinguished as regards the technical issues they were asked to address. Yet, their explanations of the chemistry of the slurry, the understanding they conveyed of the papermaking process that occurred during the Stora Enso trials, and their professional opinions concerning the scientific issues in contention differed fundamentally. As a matter of scientific fact relevant to the resolution of the instant disputes, those conflicting views cannot all be right, nor can the divergences be fully reconciled. Consequently, insofar as the Court relies upon the opinions and analyses of the experts for this purpose, on balance it gives an edge to Pelton, whose testimony and report the Court credits as more compelling.
Given the large contrast among the experts’ testimony, the Court found several considerations as persuasive. First, the Court takes note that Pelton’s doctorate education, work, professional expertise and writings more closely derive from and relate to the chemistry of the papermaking industry that is at issue here. As MTI points out, Waller’s professional training and specialty, whatever his experience in this field, is as a mechanical engineer, not a chemist, and Cummins admitted at trial that the range of his professional specialty and experience did not extend to the pa-permaking industry. Second, as regards some material issues elaborated below where the analysis and opinions of the experts disagreed sharply, the Court found Pelton’s views of the chemistry and technology both more plausible and more convincing, not only in itself, but in part as well by reason of some material gaps or inconsistencies in the testimony of Omya’s experts. And third, having reviewed the experts’ reports, observed their respective presentations at trial during the parties’ direct case presentations and under cross-examination, and after gauging their overall professional reliability and demeanor in this context, the Court found Pelton’s testimony the more creditable on these grounds as well.
B. MATERIAL DIFFERENCES
Among the material issues over which the parties and their experts strongly disagreed, the Court found two .that are particularly central to the questions the Court must address: the function of the deculator in the Stora Enso papermaking machine and, somewhat related, the length of time that the carbon dioxide used in the trial remained dissolved and unconverted in the paper furnish, a duration that consequently determined the amount of carbon dioxide which remained available to form carbonic acid and bicarbonate. How these disputes are resolved substantially guides the adjudication of the issues before the Court.
1. Function of the Deculator
As summarized above, MTI, relying on Pelton’s testimony, asserts that the deculator in the Stora Enso papermaking machine operated to remove undissolved air or gas bubbles, not dissolved gas, from the paper furnish, and that the carbon dioxide used in the test remained dissolved and recycling in the slurry long enough for all of it to convert to carbonic acid, which in turn formed bicarbonate, each compound in the requisite amount to meet the Weak Acid Requirement. (See Trial Tr. 119, 11. 15-21; MTI Post-Trial Mem. at 14.) By contrast, Omya, citing Waller’s testimony, contends that a deculator removes dissolved gas from the slurry and that therefore, at the 2004 SENA Trial, all of the dissolved carbon dioxide injected into the furnish that did not convert to carbonic acid in the relatively small reaction time available was removed. Omya states that the unconverted carbon dioxide removed comprised the bulk of the amount used.
Clearly these two claims regarding the role performed by a significant component of a large machine employed in the paper-making industry are at odds. Absent some technical principle not presented to the Court on this record, one or the other view must be incorrect. Thus, in part for the reasons stated above regarding the respective experts’ credentials, relevant knowledge of and experience in the paper-making industry, and their overall persuasiveness, the Court credits Pelton’s testimony on this point.
Pelton’s view comports with a more technically sensible and practical understanding of the chemistry and operation of the papermaking system the parties described. The Court finds it doubtful that carbon dioxide injected into the system at a point located a relatively short distance from the deculator, while the slurry was moving at a speed of approximately 50 miles per hour, would all promptly dissolve, only to be pumped immediately thereafter into the deculator, where the bulk of the gas would then be removed from the furnish, leaving only a minimal amount of it enough time to convert to carbonic acid.
2. Reaction Time and Amounts of Converted Carbon Dioxide in the System
The proper function that the deculator performed at the SENA August Trial significantly shapes the determination of the other major issue about which the parties and their experts acutely differ: the time during which the carbon dioxide used in the test remained dissolved in the paper furnish and available to react with the water in the system and, as a result, the amount of carbonic acid formed during that period. For the reasons described above, even if Omya’s view of the function of the deculator were correct, the Court remains more persuaded by Pelton’s explanation and does not find Omya’s analysis regarding the central issues compelling. Omya posits that all of the carbon dioxide injected immediately dissolved in the paper furnish and was then removed by the deculator, and that the carbon dioxide was thus present in the slurry for only a very limited period of time, not long enough to convert to carbonic acid in an amount sufficient to meet the limitation of the Weak Acid Requirement. This theory leaves open to question how the carbon dioxide could have performed its chemical purpose of reacting with water to produce enough carbonic acid to regulate the pH of the slurry. In this regard, the Court notes, as also pointed out by MTI, that Waller’s presentation was not consistent.
At trial Waller repeatedly and unequivocally stated that all of the carbon dioxide added to the slurry dissolved. (See Trial Tr. at 238,11. 21-22; 239, 11. 9-10.) In his report, however, Waller stated that “only a small percentage of carbon dioxide dissolves in water....” (See id. at 4 (“Only some of the C02 that is injected into the furnish will dissolve.”).) In another part of the report Waller states: “Assuming that 25% of the C02 used dissolved in the furnish (in fact, far less than that), closer to 1% would have dissolved.” (Id. at 5.) Omya does not address this large discrepancy in its expert’s testimony. But the inconsistency is important because it touches upon another major point which bears on the calculation of the amount of carbonic acid formed and on which the experts’ presentations clashed.
The amount of carbon dioxide dissolved in the furnish, the time it takes for it to react with the water, and the duration of the dissolved carbon dioxide in the system should be major factors determining how much carbonic acid was formed. In this regard, Waller testified that the reaction time is approximately one minute. (See Trial Tr. at 250, 11. 7-9). This assumption is not consistent with other aspects of his analysis. There is evidence from Stora Enso officials who conducted the test that it took the furnish under one minute, and most likely between 15 and 45 seconds, to travel to the headbox from the point where the carbon dioxide was injected into the system. (See Deposition of Jesse A. De-Witte, dated November 20, 2005, at 29, 11. 1-13.) Waller’s testimony that the conversion reaction takes approximately one minute suggests that the carbon dioxide would not have had sufficient time to fully dissolve before it reached the headbox. However, Waller testified at trial that all of the carbon dioxide injected into the slurry dissolved (see Trial Tr. at 239) and that the carbon dioxide conversion reached a state of equilibrium. (See Trial Tr. at 214, 11. 19-21; 243, 11. 5-9). This apparent inconsistency raises substantial questions about Waller’s assumptions and analysis.
Pelton, supported by references to other chemistry literature, stated that the reaction time for carbon dioxide to dissolve and react with water takes only a matter of seconds, thus allowing longer opportunity for more of the dissolved carbon dioxide to convert into carbonic acid. (See Trial Tr. at 80, 11. 3-17.) Thus, the analysis contained in Waller’s report effectively assumed a static system, and his computation of the amount of carbonic acid formed seems based on a snapshot of any single moment, rather than the aggregate over the course of the entire test. At trial, however, Waller appeared to have modified this position by stating the carbonic acid amount he calculated extended over the duration of the entire experiment. (See Trial Tr. at 222.) In fact, the paper furnish had water recycling and carbon dioxide continually being injected into it. As noted above, it took the furnish under one minute and more like 15 to 45 seconds to travel to the headbox from the point where the carbon dioxide was injected into the system. (See Trial Tr. at 118.) These discrepancies again raise questions about whether under Waller’s theory there was sufficient reaction time for all of the carbon dioxide to dissolve before the portion of it that remained unconverted was removed, even if the Court accepted his version of how the deculator functioned.
On these points as well the Court finds Pelton’s report and testimony explaining the chemistry of the system more persuasive. If all of the carbon dioxide did dissolve in the slurry but, contrary to Waller’s testimony, it was not removed by the deculator, but rather, as Pelton argued, the carbon dioxide remained in the system through fresh injections and by continuous recirculating in the furnish, it would have been available for reaction long enough to create in the aggregate greater quantities of carbonic acid, which in turn promptly disassociated to generate bicarbonate. The process would continue recycling until all of the dissolved carbon dioxide would have been consumed by the chemical reactions. By this means, the amount of carbonic acid created would have been greater than that resulting from Waller’s assumptions and analysis, and more consistent with Pelton’s calculation.
The Court’s acceptance of Pelton’s theory and analysis of the chemistry and operation of the paper furnish at the 2004 SENA Trial serves as the technical foundation for the Court’s own determinations of the questions it is asked to resolve. With this scientific support as framework for its determination, and upon consideration of the entire record before it, the Court concludes that the Weak Acid Requirement was met at the 2004 Stora Enso Trial, both literally and under the doctrine of equivalents. The Court addresses these findings and explains its reasoning below.
IV. FINDINGS
A. CARBON DIOXIDE AND THE WEAK ACID REQUIREMENT
The Court finds the evidence mixed, perhaps at best evenly divided and thus inconclusive, on the issue of whether the carbon dioxide used at the 2004 SENA Trial by itself literally met the Weak Acid Requirement. MTI produced evidence, through Pelton’s testimony and scientific literature, supporting the proposition that carbon dioxide may be considered a Lewis acid. The issue before the Court, however, entails a broader inquiry: whether, giving the terms of MTI’s patent claims their ordinary and customary meaning, the phrase “weak acid” would have been regarded by a person of ordinary skill in the chemical arts in 1991 as encompassing the classification of carbon dioxide as a weak acid, and whether “weak acid” referred to a Lewis acid, rather than only a Bronsted acid.
A preliminary step of the analysis is whether the skilled person the standard refers to is one possessing sufficient technical knowledge and ordinary skill relating to the general art in question, here the “chemical arts,” or whether the inquiry may be further confined to a narrower sub-specialty within a particular technical field or industry. MTI’s argument suggests this more limited standard: that persons such as Pelton and Passaretti skilled in the specialized chemistry of papermak-ing would understand that carbon dioxide is a Lewis acid within the literal meaning of the weak acid element of the Patents and would function as such in a paper furnish. {See Trial Tr. at 91,11. 1-14; 302, 11. 12-25; 303, 11. 1-7.) However, MTI’s argument is somewhat undercut in that, in its application to the Patent and Trademark Office (“PTO”) for the Patents, MTI noted that the term “weak” in the reference to “weak acid” is well known to those “skilled in the chemical arts” and has a well-established meaning in that context. There is no indication that MTI sought to narrow the relevant technical field to the chemical arts specifically associated with the papermaking industry.
Omya, on the other hand, implicitly suggests the application of a more general standard, enlarging the field more broadly to encompass persons skilled in the chemical arts, not necessarily those involved in papermaking. By this measure, Omya, citing the testimony of Waller and Cum-mins, contends that the reference to weak acids means only a Bronsted acid — a proton donator that partially ionizes in water — and points out that only Bronsted acids are chemically classified as “weak” or “strong” in accordance with the scale of pKa values, as opposed to the “soft” and “hard” terminology applied to Lewis acids.
The Court concludes that the skilled person the standard refers to is appropriately defined here as a person with skill in the specialized art of papermaking. A “person of ordinary skill in the art” is defined as “a hypothetical person who is presumed to be aware of all the pertinent prior art.” Custom Accessories, Inc. v. Jeffrey-Allan Indus., Inc., 807 F.2d 955, 962 (Fed.Cir.1986). “Prior art” is elsewhere defined as that which is “reasonably pertinent to the particular problem with which the inventor was involved.” Stratoflex, Inc. v. Aeroquip Corp., 713 F.2d 1530, 1535 (Fed.Cir.1983). These definitions, together with case law applying the “person of ordinary skill in the art” standard, suggest that the more restrictive formulation of the standard is appropriate. See, e.g., Cargill, Inc. v. Sears Petroleum & Transp. Corp., 334 F.Supp.2d 197, 215-16 (N.D.N.Y.2004). In Cargill, which involved a patent for a chemical composition used in road de-icing, the court weighed the parties’ competing definitions of “one with ordinary skill in the art” and concluded that the skilled person possessed specialized experience in road de-icing and training in chemistry, rather than chemistry training alone. See id.
If, as this authority suggests, the more restrictive field were the applicable test, MTI’s position would be somewhat undercut by evidence emanating from its own sources. As Omya points out, at his deposition in an earlier phase of this litigation, apparently before the question of whether carbon dioxide may qualify as a Lewis acid arose, Pelton, a person with skill in the specialized art of papermaking, offered a definition of an acid that reflected the Bronsted definition; he made no mention then of a Lewis acid. Likewise, Bruce Evans, another MTI representative, testified at a deposition that an acid is a compound that in an aqueous solution donates protons.
The Court concludes that the record does not contain sufficient evidence to support a compelling determination with regard to whether, in the context of the Patents, carbon dioxide alone would have been classified as a weak acid within the ordinary and customary meaning of the term to a person of ordinary skill in the papermaking arts at the time of issuance. To this extent, MTI did not meet its burden to establish by a preponderance of the evidence its claim that the Weak Acid Requirement was literally met at the 2004 SENA Trial by the use of carbon dioxide alone.
B. CARBONIC ACID IN COMBINATION WITH OTHER WEAK ACIDS
The Agreement calls for the Court to determine whether the Weak Acid Requirement was satisfied at the 2004 SENA Trial by the use of carbonic acid alone or in combination with other weak acids. The parties agree that carbonic acid falls within the chemical definition of a weak acid. It seems undisputed as well, since Waller testified to this effect (see Trial Tr. at 253), that bicarbonate may also be classified as a weak acid. MTI contends that all of the carbon dioxide infused into the paper furnish during the 2004 SENA Trial remained dissolved and that during the time it was present in the system the requisite amount of carbonic acid formed, which then disassociated and converted to bicarbonate. According to MTI, the entire amount of carbon dioxide was consumed, in the process forming enough carbonic acid, and an equivalent amount of bicarbonate, to meet the Weak Acid Requirement, alone or in combination. Pelton calculated the amounts of carbonic acid and bicarbonate yielded to be 4.9 weight percent of the calcium carbonate in the furnish.
The Court credits the testimony of Pel-ton on this point. Accepting Pelton’s theory of the chemistry of the reaction of carbon dioxide in the paper furnish during the 2004 SENA Trial, as supported by other evidence in the record, the entire amount of carbon dioxide used in the test dissolved in the water circulating in the system and, through continuous recycling and fresh injections during the course of the seven-day trial, had sufficient reaction time in the furnish to disassociate and to be fully consumed in converting to carbonic acid, which in turn formed bicarbonate, in amounts that in the aggregate exceeded 0.1 weight percent of the calcium carbonate in the slurry. Accordingly, the Court finds that the carbonic acid generated by the reaction of carbon dioxide and water, alone or in combination with the bicarbonate that the carbonic acid in turn produced, satisfied the literal terms of the Weak Acid Requirement.
C. THE DOCTRINE OF EQUIVALENTS AND PROSECUTION HISTORY ESTOPPEL
The Agreement asks the Court to address the proper application of the doctrine of equivalents and prosecution history estoppel as they relate to the Weak Acid Requirement, to the extent raised by the parties. MTI claims that under the doctrine of equivalents, by means of the carbon dioxide used at the 2004 SENA Trial, Omya infringed the Patents, insofar as the carbon dioxide or the bicarbonate to which it ultimately converted, through an intermediate state as carbonic acid, performed substantially the same function of the weak acid substantially the same way to achieve substantially the same result that the Patents teach. Omya counters that in statements MTI made to the PTO to obtain issuance of the Patents, MTI asserted that the terms “weak” and “weak acid” were well established in the chemical arts and were to be read in accordance with their ordinary and customary meaning in that context. On this basis Omya contends that because at that time the recognized definition of a weak acid to persons skilled in the chemical arts was a Bronsted acid, MTI is therefore bound by those representations and should now be estopped from claiming that carbon dioxide may be classified as a Lewis acid and a weak acid. To address this dispute the Court reviews the standards that govern the application of these doctrines.
1. Doctrine of Equivalents
The judicial doctrine of equivalents emerged as a means to recognize patent infringement in the case of a product or process that “does not literally infringe upon the express terms of a patent claim [but] may nonetheless be found to infringe if there is ‘equivalence’ between the elements of the accused product or process and the claimed elements of the patented invention.” Warner-Jenkinson Co., Inc. v. Hilton Davis Chem. Co., 520 U.S. 17, 21, 117 S.Ct. 1040, 137 L.Ed.2d 146 (1997) (citing Graver Tank & Mfg. Co. v. Linde Air Prods. Co., 339 U.S. 605, 70 S.Ct. 854, 94 L.Ed. 1097 (1950)). Thus, the doctrine recognizes that if a patent were interpreted unremittingly by the express language of its claims alone, the value to the inventor would be diminished. The rule thus serves to acknowledge and mitigate the limitations of literalism, and to enlarge the scope of patent protection the inventor can claim. As the Supreme Court noted in Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki, Co., Ltd.: “[T]he nature of language makes it impossible to capture the essence of a thing in a patent application.” 535 U.S. 722, 731, 122 S.Ct. 1831, 152 L.Ed.2d 944 (2002).
Implicitly, the enhanced patent rights that the doctrine of equivalents warrant encompass two basic concepts. First is that at the time of prosecution of the patent the applicant cannot reasonably be expected to foresee and express in anticipatory language every technical advance and interchangeable element by which the invention may later be altered, however insubstantially, to achieve essentially the same product or process. Second, in going beyond the literal terms of the patent to validate claims to equivalents, what the doctrine endeavors to embody within its protection is the “essence” of the concept and the “range of its novelty” to which the inventor seeks to give expression in the wording of the claims, but that the constraints of language and foresight do not allow capturing those qualities with complete precision. Id.; see also Atlas Powder Co. v. E.I. du Pont De Nemours & Co., 750 F.2d 1569, 1582 (Fed.Cir.1984) (“Although there is no legally recognized ‘essence’ or ‘heart’ of the invention in determining validity ... it can be applicable in a determination of infringement under the doctrine of equivalents.”) (internal citations omitted) (citing Medtronic, Inc. v. Cardiac Pacemakers, Inc., 721 F.2d 1563, 1567 (Fed.Cir.1983)).
Accordingly, an accused device or method should be deemed equivalent, and thus not an insubstantial alteration of an element of a patented technology, if in its basic elements it employs the essence of the concept on which the claimed novelty of the original invention is fundamentally grounded, as evidenced by substantial similarities in the role each element plays in the operation of the claimed product, the way it functions and the result obtained. See id. (“Unimportant and insubstantial substitutes for certain elements could defeat the patent and its value to investors could be destroyed by simple acts of copying.”).
What constitutes equivalency, the Supreme Court counseled in Graver Tank, “is not the prisoner of a formula and is not an absolute to be considered in a vacuum,” nor does it “require complete identity for every purpose and in every respect.” 339 U.S. at 609, 70 S.Ct. 854. Rather:
In determining equivalents, things equal to the same thing may not be equal to each other and, by the same token, things for most purposes different may sometimes be equivalents. Consideration must be given to the purpose for which an ingredient is used in a patent, the qualities it has when combined with the other ingredients, and the function which it is intended to perform. An important factor is whether persons reasonably skilled in the art would have known of the interchangeability of an ingredient not contained in the patent with one that was.
Id. (emphasis added).
As it developed in early applications, the doctrine was invoked in patent disputes in which the claimed equivalence pertained to mechanical components employed in the competing devices. Particularly germane to the matter at hand, in later extensions, as the chemical arts advanced, the same principles were also applied to inventions entailing chemical compositions and processes, where the claim of equivalence involved chemical ingredients or processes that embodied the essence of a component of the patented product or method. Id.
Two expressions of the doctrine of equivalents are generally articulated by the courts. The earlier version, ordinarily more apt for mechanical devices, enabled the patentee to invoke equivalency if the accused product “ ‘performs substantially the same function in substantially the same way to obtain the same result.’ ” Graver Tank, 339 U.S. at 608, 70 S.Ct. 854 (quoting Sanitary Refrig. Co. v. Winters, 280 U.S. 30, 42, 50 S.Ct. 9, 74 L.Ed. 147 (1929)). As refined by Graver Tank, a case involving chemical compositions, a second formulation places greater emphasis on the substantiality of the alteration: “whether under the circumstances the change was so insubstantial that ... invocation of the doctrine of equivalents was justified.” Id. at 610, 70 S.Ct. 854. In the most recent applications of the doctrine, the Federal Circuit has framed the basic inquiry of equivalency as grounded on the insubstantiality standard, while employing the function-way-result test as one consideration to be weighed. See Eagle Comtronics, Inc. v. Arrow Communication Labs., Inc., 305 F.3d 1303, 1315 (Fed.Cir.2002). In either event, the theory recognizes that if two products operate substantially the same way and achieve substantially the same result, “ ‘they are the same, even though they differ in name, form or shape.’ ” Graver Tank, 339 U.S. at 608, 70 S.Ct. 854 (quoting Union Paper-Bag Mach. Co. v. Murphy, 97 U.S. 120, 125, 24 L.Ed. 935 (1877)).
Recognizing the conflict that broad application of the doctrine of equivalents poses for the definitional and public notice purposes of the patent statute’s claiming requirement, the Supreme Court in Warner-Jenkinson elaborated a further limitation. It declared that the doctrine “must be applied to individual elements of the claim, not to the invention as a whole.” 520 U.S. at 29, 117 S.Ct. 1040. Accordingly, the Supreme Court instructed that the essential inquiry in applying the test of substantiality is:
Does the accused product or process contain elements identical or equivalent to each claimed element of the patented invention.... [A]n analysis of the role played by each element in the context of the specific patent claim will thus inform the inquiry as to whether a substitute element plays a role substantially different from the claimed element.
Id. at 40,117 S.Ct. 1040.
Unlike the temporal rules that govern literal infringement, which are designed to prevent enlargement of the scope and protection for an invention by construing its language in accordance with the ordinary and customary meaning of the terms of the claims as of the time the patent issued, the doctrine of equivalents focuses on a different point in time: knowledge of the art and interchangeability of elements as of the date of the alleged infringement. See id. at 37, 117 S.Ct. 1040 (“Insofar as the question under the doctrine of equivalents is whether an accused element is equivalent to a claimed element, the proper time for' evaluating equivalency ... and thus knowledge of interchangeability between elements — is at the time of infringement, not at the time the patent was issued.”); Atlas Powder Co., 750 F.2d at 1581 (“It is not a requirement of equivalence ... that those skilled in the art know of the equivalence when the patent application is filed or the patent issues. That question is determined as of the time infringement takes place.”).
Moreover, knowledge of the interchangeability of elements is determined by objective factors. See Graver Tank, 339 U.S. at 608, 70 S.Ct. 854 (“An important factor is whether persons reasonably skilled in the art would have known of the interchangeability of an ingredient not contained in the patent with one that was.”); see also Warner-Jenkinson, 520 U.S. at 36, 117 S.Ct. 1040 (noting that though independent experimentation by an infringer may not always reflect on the objective question of whether a person skilled in the art would have known of the interchangeability between two elements, “in many cases it would likely be probative of such knowledge”). These rules recognize that judging the alleged equivalency of elements of a device or process as of the point of patent issuance would unduly curtail the coverage of patent rights by barring the original inventor from enforcing approved claims against methods or devices later developed with refinements of the technology. Absent application of equivalence, such an adverse result would occur even if fundamentally the accused product incorporates the creative essence and technology embodied in the original invention and is thus not substantially different, insofar as it demonstrably employs substantially the same elements and operates substantially the same way to achieve substantially the same result as the patented product.
2. Prosecution History Estoppel
Prosecution history estoppel is a rule of patent construction that works in tandem with the doctrine of equivalents, ensuring that the latter “remains tied to its underlying purpose.” Festo, 535 U.S. at 734, 122 S.Ct. 1831. While the rule of equivalence extends protection to a patent owner over insubstantial modifications of the invention that may not be literally expressed in the claim as patented, but that could be developed by minor alterations, “when ... the patentee originally claimed the subject matter alleged to be infringed but then narrowed the claim in response to a rejection, he may not argue that the surrendered territory comprised unforeseen subject matter that should be deemed equivalent to the literal claims of the issued patent.” Id. at 733-34, 122 S.Ct. 1831.
As most recently elaborated by the Supreme Court in Festo, application of prosecution history estoppel takes into account several considerations. These standards provide that: (1) the inventor knew of the terms describing both a broader and the narrower claim; (2) the choice to narrow the claim or disavow or surrender claim territory or particular equivalents must be made by the applicant affirmatively; (3) ordinarily the narrowing amendment or statement was made as a condition for obtaining the patent to protect its validity, or to comply with any requirement of the Patent Act, especially in the face of a claim rejection by the PTO that would have rendered the invention unpat-entable; (4) the patentee’s decision to narrow the particular claim raises a presumption that the territory surrendered by the claim amendment is not the equivalent of the territory claimed; and, (5) estoppel should not apply to bar claims of equivalents that the patent application could not reasonably be held to have literally expressed and surrendered in an amendment or representation made during prosecution, in particular where the equivalents may have been unforeseeable at the time of the narrowing statement. See id. at 735-40, 122 S.Ct. 1831. “[T]he patentee must show that at the time of the amendment one skilled in the art could not reasonably be expected to have drafted a claim that would have literally encompassed the alleged equivalent.” Id. at 741, 122 S.Ct. 1831. Thus, the scope of prosecution history estoppel is limited to claim-narrowing amendments and representations that were foreseeable and that affirmatively surrendered the particular equivalents in contention. “There is no reason why a narrowing amendment should be deemed to relinquish equivalents unforeseeable at the time of the amendment and beyond a fair interpretation of what was surrendered.” Id. at 738, 122 S.Ct. 1831.
In synthesis, viewed together, the doctrines of equivalents and prosecution history estoppel encapsulate various central principles that go to the core and mark the contours of patent rights, a body of law which as a whole reflects a great confluence of human energies, ends and limitations. These principles are given expression through several concepts fundamental to the law of patents that are prominent in the issues the instant case presents, and are touched upon here as a helpful backdrop to their application in the discussion that follows. First, patent doctrines are ultimately designed to validate original invention, to this end conferring a bounty on inventors’ creativity and innovation, rewarding their ambition, initiative and diligence, and thereby providing incentive for novel contributions to useful arts. Second, they acknowledge the shortcomings of language, underscoring the limitations of words to capture with precision the full scope, both actual and potential, of the novelty and operation of new technology. Third, they recognize the practical bounds of foresight, in other words, the limited ability of an inventor, prior to prosecuting a patent application, to anticipate advancements of the art and to experimentally test every conceptual variation and mechanical configuration by which a new product or process may also function to achieve a claimed result.
Fourth, through claim disclosure, equivalents, estoppel and related principles, patent law also reaffirms the proposition that truly new ideas are a free commodity and that no one should possess an unbounded monopoly on any particular unique concept. In consequence, the creation and advancement of original arts reflect the practical workings of an extensive process akin to a conceptual marketplace. Given enough passage of time, combined with ever-expanding spheres of knowledge, the outer reaches of human imagination, the virtually infinite variety of natural and synthetic ingredients supplied by the world around us, and a large pool of persons similarly animated by ambition and creative forces, new products and processes are bound to develop. Hence, it is not unusual that, by operation of the laws of probability and contingencies, out of this amalgamation of circumstances an inspired mix would evolve from which one or more inventions could emerge independently that operate to attain a result closely similar to that achieved by another known device employing substantially different means and innovative concepts.
By the same token, these principles also recognize certain commonplace realities, the real world of expediency borne of human competition and commerce. The same creative energies can also be harnessed to motivate tinkering at the margins of existing technology and impel inventiveness to devise a product ostensibly novel, but that in reality amounts to a minor modification of one already patented. In this instance, creativity is more derivative than original; the inventor is moved less by uncharted novelty than by the known or potential success of a concept engendered by another. Craft and language claiming a technological breakthrough is then employed not to innovate, but to imitate, edging as close to the line, and tapping as much of the creative essence of prior art, as verisimilitude might lawfully allow.
The challenge in patent controversies arising from the operation of these principles, as is the case of the dispute now before the Court, is to ascertain on which side of the line the doctrinal circumstances and the parties’ conduct fall.
3. Application of Doctrines
As a backdrop for application of the doctrines of equivalents and prosecution history estoppel, the Court notes some aspects of the parties’ dispute that present novel points. At the 2003 SENA Trial, Omya employed phosphoric acid in the paper furnish as the substance designed to function as the weak acid feature of the system tested. The parties agree that the experiment worked to lower the pH of the