N.V. Akzo v. E.I. Dupont de Nemours

• Decision Date: 05 February 1987
• Docket Number: Nos. 86-1327,86-1358,s. 86-1327
• Citation: 810 F.2d 1148,1 USPQ2d 1704
• Parties: N.V. AKZO, Aramide Maatschappij v.o.f., Appellant/Cross-Appellee, v. E.I. DUPONT de NEMOURS, Appellee/Cross-Appellant. Appeal
• Court: U.S. Court of Appeals — Federal Circuit

Page 1148

810 F.2d 1148

1 U.S.P.Q.2d 1704

N.V. AKZO, Aramide Maatschappij v.o.f., Appellant/Cross-Appellee, v. E.I. DUPONT de NEMOURS, Appellee/Cross-Appellant.

Appeal Nos. 86-1327, 86-1358.

United States Court of Appeals Federal Circuit.

Feb. 5, 1987.

C. Frederick Leydig, Leydig, Voit & Mayer, Ltd., Chicago, Ill., argued for appellant/cross-appellee. With him on the brief were Charles S. Oslakovic, John Kilyk, Jr., Norval B. Galloway and Robert F. Green, Leydig, Voit & Mayer, Ltd., of counsel. Also on the brief were Denis McInerney and P. Kevin Castel, Cahill, Gordon & Reindel, New York City and Robert H. Falk, Hubbard, Thurman, Turner & Tucker, of Dallas, Tex.

Joseph Fitzpatrick, Fitzpatrick, Cella, Harper & Scinto, New York City, argued for appellee/cross-appellant. With him on the brief were John A. O'Brien, Henry J. Renk, Charles P. Baker, Laura A. Bauer and Bruce C. Haas. Also on the brief were Robert H. Patterson, Jr. and Anne Marie Whittenmore, McGuire, Woods & Battle, Richmond, Va. and Robert C. Kline, E.I. DuPont de Nemours, Wilmington, Del.

Before MARKEY, Chief Judge, DAVIS and NIES, Circuit Judges.

DAVIS, Circuit Judge.

Akzo N.V. and Aramide Maatschappij v.o.f. (Akzo) brought suit against E.I. Du-Pont de Nemours & Co. (Du Pont) in the

                United States District Court for the Eastern District of Virginia alleging that Du Pont had deliberately infringed U.S. Patent No. 4,308,374 ('374 patent) issued to Akzo.  Akzo sought an injunction prohibiting Du Pont from infringing the '374 patent, an accounting for past damages, a determination that Du Pont's alleged infringement was willful, and an award of attorney fees.  Du Pont counterclaimed, asserting that the '374 patent was invalid under 35 U.S.C. Sec. 103;  Du Pont also asserted that Akzo had engaged in inequitable conduct before the Patent and Trademark Office (PTO).  The District Court, in a detailed and well-reasoned opinion, held the '374 patent invalid under 35 U.S.C. Sec. 103 and therefore not infringed, but concluded that Akzo had not engaged in inequitable conduct before the PTO.   Akzo v. E.I. du Pont de Nemours, 635 F.Supp. 1336, 230 USPQ 263 (E.D.Va.1986).  We affirm
                

I. BACKGROUND ¹

Du Pont and Akzo have both been involved in the commercial manufacture of high-strength, low-density synthetic aramid fibers from poly-p-phenyleneterephthalamide (PPD-T). ² See Akzo N.V., Enka B.V., Aramide Maatschappij v.o.f., and Akzona Inc. v. U.S. International Trade Commission and E.I. duPont de Nemours & Co., 808 F.2d 1471 (Fed.Cir.1986). These fibers have a number of commercial applications including roping, tires, aviation parts, bullet-proof clothing, and boat hulls. In order to produce a synthetic fiber with high tensile strength, high viscosity solutions of PPD-T must be prepared. The synthetic fibers are then spun from these high viscosity solutions. The patent at issue--Akzo's '374 patent--describes a process for a solvent system whereby PPD-T having an inherent viscosity ³ of at least 2.5 can be made by using N-methylpyrrolidone (NMP) containing at least 5% by weight calcium chloride (CaCl2 ) salt.

In the mid-1950's, Du Pont began research on aromatic polyamides with the aim of producing a high-tensile strength synthetic fiber. In order to spin a satisfactory fiber, the aromatic polyamides must first be dissolved in a suitable medium. In 1957, Du Pont conducted research on a number of polymerization solvent systems including NMP combined with inorganic salts such as lithium chloride (LiCl) and CaCl2 . In 1969, Du Pont targeted PPD-T as the polymer of choice to produce a high-strength synthetic fiber. Researchers investigated a number of polymerization solvent systems for use with PPD-T, but in 1971 Du Pont elected to use hexamethylphosphoramide (HMPA) as a solvent system to yield PPD-T with the high inherent viscosity required for spinning into a finished fiber. Du Pont immediately discontinued research into alternative solvent systems. There were, however, problems with the HMPA solvent system. Du Pont was aware that HMPA was toxic to humans, and in 1975 discovered that it could be carcinogenic to animals. Upon discovering the possible carcinogenic effect, Du Pont began in September 1975 to research again into possible alternative solvent systems. Akzo scientists informed researchers at Du Pont that they had been able to produce a high inherent viscosity PPD-T fiber without using HMPA as a solvent, but did not specify the alternative solvent system. ⁴ Prior to 1975, Du Pont had not used NMP in the polymerization of PPD-T, but in 1969 it had used NMP with LiCl in the polymerization of another fiber, 1,4 poly-p-benzamide (Fiber B). In addition, in 1969-70, Du Pont had been able to make a third fiber, chloro-PPD-T, using dimethylacetamide (DMAc) or NMP as the polymerization Early work on an alternative polymerization solvent system by Beers, Katz, and Miller of Du Pont included experimentation with NMP with various salts. It was well-known in the industry at that time that NMP was an effective amide solvent and that the addition of salts such as LiCl and CaCl2 would increase solubility. At first, the researchers concentrated on using LiCl as the inorganic salt, but in early 1976, began to experiment with CaCl2 , which was more economical and less toxic than LiCl. By February 1976, Du Pont had succeeded in making high molecular weight PPD-T polymer with a high inherent viscosity using an NMP/CaCl2 solvent system.

medium in combination with LiCl or CaCl2 , but achieving much better results with LiCl.

In 1971, at the time when Du Pont had selected HMPA as its solvent of choice, two Akzo researchers, Vollbracht and Veerman, began to conduct solubility studies on PPD-T. Several polymerization systems were investigated, including combining NMP with certain salts, among them LiCl and CaCl2 . Results of early studies led Vollbracht and Veerman to the conclusion that LiCl performed better than CaCl2 , but because of the high cost of LiCl compared with CaCl2 the researchers continued experiments to discover whether CaCl2 could be an effective substitute. In April 1974, after conducting three months of intensive investigation on model substrates, Vollbracht and Veerman submitted an invention disclosure on the preparation of PPD-T in NMP/CaCl2 . Akzo filed a patent application in the Netherlands on February 21, 1975. On January 19, 1976, Akzo filed an application for a U.S. Patent.

On June 1, 1976, Du Pont also filed an application for a U.S. Patent for an NMP/CaCl2 solvent system. The technology in the Du Pont application was almost identical to the Akzo application except that Du Pont expressed CaCl2 in moles of CaCl2 per mole of PPD-T while Akzo expressed CaCl2 as weight percent of PPD-T. At the time of application, Du Pont concluded that it would be a close question whether the solvent system would be patentable based on the prior art. After its patent application was filed, Du Pont discovered two additional prior art references: the Federov reference and the Asakura '686 patent.

The examiner declared an interference between Akzo and Du Pont in May 1977. Du Pont then withdrew its application concluding that Akzo would prevail in an interference but that the Asakura '686 patent would render the NMP/CaCl2 solvent system obvious based on the prior art.

Akzo's U.S. applications for the '374 patent were rejected eight times by the PTO on Sec. 103 grounds, and only after more than five years, including two refilings, did the '374 patent issue in December 1981.

The examiner's initial rejections were based on his conclusions that Akzo's NMP/CaCl2 solvent system would have been obvious under Sec. 103 in the light of the prior art references. Only after Akzo stipulated in each of its claims that a minimum percentage by weight of "CaCl2 of at least 5%" was essential, and advanced an argument that this minimum 5% by weight critical limit was not obvious over the prior art, did the examiner allow the patent to issue.

II. VALIDITY

We start by repeating the established rules for testing the validity of a patent. Under 35 U.S.C. Sec. 282, patents are presumed valid. E.g., Roper Corp. v. Litton Systems, Inc., 757 F.2d 1266, 225 USPQ 345 (Fed.Cir.1985); Stratoflex, Inc. v. Aeroquip Corp., 713 F.2d 1530, 218 USPQ 871 (Fed.Cir.1983). The party asserting patent invalidity must first establish a prima facie case of invalidity and must carry the burden of persuasion until the final decision. Id. at 1534, 218 USPQ at 875. In cases challenging patent validity, a challenger has an especially heavy burden because of the deference given to decisions of the patent examiner. American Hoist & Derrick Co. v. Sowa & Sons A. Under these principles Akzo challenges the District Court's conclusion of invalidity, contending, for one thing, that the District Court merely gave lip service to the Sec. 282 presumption of validity in declaring the '374 patent invalid. On the contrary, not only did the District Court conclude that "the evidence presented at trial shows clearly and convincingly that the invention as a whole would have been obvious to one skilled in the art," 635 F.Supp. at 1353, 230 USPQ at 275, but the court also went on to elaborate with specificity how it came to this conclusion, citing and discussing prior art. Moreover, the District Court found that Akzo had represented the criticality of the "at least 5% CaCl2 " limitation claimed in the patent, noting that the examiner had permitted the '374 Akzo patent to issue only after Akzo had made that limitation in each and every one of the claims of the '374 patent. The court found credible the evidence presented at trial that 5% was not actually a critical percentage for the NMP/CaCl2 and that Akzo had knowledge that a commercial fiber could be made with less than 5% by weight CaCl2 . The court then concluded that neither the examiner nor any other reasonable examiner would have permitted the Akzo patent to issue...