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Federal Circuit again decides inequitable conduct issueMarch 29, 2006

In Atofina v. Great Lakes Chemical Company, the Federal Circuit considered the issues of inequitable conduct, anticipation, and, like most appeals, claim construction. Atofina owns U.S. Patent No. 5,900,514, which relates to a method of synthesis of difluoromethane using, among other things, a chromium catalyst. Great Lakes produced difluoromethane using a mixed metal catalyst that contained chromium and another element which they maintained as a trade secret. Chromium was still necessary for Great Lakes’ process to function, but the presence of the additional element enhanced both the selectivity of the reaction and the life of the catalyst. The district court held that Great Lakes’ process did not infringe Atofina’s patent, that several claims of the patent were anticipated by a Japanese publication, and that the patent was unenforceable due to inequitable conduct. The Federal Circuit affirmed the district court’s construction of the term ‘chromium catalyst’ as essentially requiring that the only active substance in the catalyst be chromium. The patent’s specification stated that the catalyst was based on ‘pure chromium (without the addition of another metal oxide),’ and that it was ‘necessary to have a catalyst containing solely chromium,’ and thus the court found that these statements (along with others) limited the scope of the term ‘chromium catalyst’ in the claim. Based on this construction, the finding of no infringement was also affirmed, as it was undisputed that Great Lakes used a catalyst that had chromium and another element. The court did find clear error in the district court’s determination that certain claims were anticipated. The Japanese reference disclosed ranges of temperature and molar ratios that did not exactly correspond to Atofina’s patent. While the court noted that in some cases the disclosure of a range may anticipate every value within that range (disclosure of a genus may anticipate every species within that genus), that was not the case here. For example, the temperature range in the Japanese publication was 100-500 degrees Celsius, whereas the claimed range was 330-450 degrees Celsius. Because of this ‘considerable difference’ in the ranges, the prior art did not disclose the claimed range with sufficient specificity to anticipate this limitation. Finally, the court also reversed the finding that Atofina’s patent was invalid for inequitable conduct. In order for inequitable conduct to be shown, material information must be withheld or a false statement made to the patent examiner with an intent to mislead or deceive the examiner. Here, Atofina did not disclose an English translation of the Japanese reference and allegedly mischaracterized its contents. The court found that the three statements made about the reference were consistent with the translated abstract Atofina had in its possession, and therefore the intent to deceive required for a finding of inequitable conduct was absent. This case is another in a number of recent cases in which the Federal Circuit has taken on the issue of inequitable conduct, and illustrates how important the duty of candor to the Patent and Trademark Office is to the eventual enforceability of a patent as well as how even an arguable violation of that duty can increase the cost of litigating a patent infringement case. For the complete decision, log on to

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