257 F.3d 1364 (Fed. Cir. 2001), 00-1441, Dow Chemical Co. v. Sumitomo Chemical Company
|Citation:||257 F.3d 1364|
|Party Name:||THE DOW CHEMICAL COMPANY, PLAINTIFF-APPELLANT, v. SUMITOMO CHEMICAL COMPANY, LTD. AND SUMITOMO CHEMICAL AMERICA, INC., DEFENDANTS-APPELLEES.|
|Case Date:||July 25, 2001|
|Court:||United States Courts of Appeals, Court of Appeals for the Federal Circuit|
Corrected: July 27, 2001
Appealed from: United States District Court for the Eastern District of Michigan Judge Victoria A. Roberts
[Copyrighted Material Omitted]
[Copyrighted Material Omitted]
Willem G. Shuurman, Vinson & Elkins L.L.P., of Austin, Texas, argued for plaintiff-appellant. With him on the brief were David P. Blanke, Adam v. Floyd, and Gregory L. Porter. Of counsel on the brief was Gwendolyn J. Samora, Vinson & Elkins L.L.P., of Houston, Texas. Also of counsel on the brief were Bruce M. Kanuch, and Joe Prieto, The Dow Chemical Company, Office of Patent Counsel, of Midland, Michigan.
Kenneth J. Burchfiel, Sughrue, Mion, Zinn, Macpeak & Seas, Pllc, of Washington, Dc, argued for defendants-appellees. With him on the brief were J. Frank Osha, Brett S. Sylvester, John T. Callahan, and Mary E. Goulet.
Before Clevenger, Rader, and Gajarsa, Circuit Judges.
Gajarsa, Circuit Judge
This is a patent infringement action. The Dow Chemical Company ("Dow") is the assignee of United States Patent No. 4,499,255 ("the '255 patent"), which is directed to a process for making high-purity epoxy resins. In 1996, Dow brought this patent infringement action against Sumitomo Chemical Company, Ltd. and Sumitomo Chemical America, Inc. (collectively "Sumitomo"), alleging that certain processes used by Sumitomo infringe the '255 patent. On June 20, 2000, the United States District Court for the Eastern District of Michigan ("district court") determined that certain limitations required by claim 1 of the '255 patent are not present in Sumitomo's processes either literally or under the doctrine of equivalents, and granted Sumitomo's motion for summary judgment of noninfringement. Dow Chem. Co. v. Sumitomo Chem. Co., No. 96-10330, slip. op. at 7-8, 25 (E.D. Mich. June 20, 2000). Dow appeals that judgment.
For the reasons discussed below, we vacate and remand for further proceedings consistent with this opinion.
The '255 patent is directed to an improvement of the process for the preparation of glycidyl ethers, or certain types of "epoxy resins." The preparation of epoxy resins was previously well known in the art. The prior method consisted of preparing glycidyl derivatives of compounds having at least one aromatic hydroxyl group or aromatic amine group per molecule by reacting such compounds with an excess of epihalohydrin ("epi") in the presence of an alkali metal hydroxide, and subsequently recovering the glycidyl derivatives. This process is commonly referred to as an epoxidation reaction. The invention disclosed by the '255 patent is directed to an improvement of this well known method of preparing epoxy resins. The improvement as claimed by the '255 patent consists of certain process conditions that must be
present during part of the epoxidation reaction process.
Epoxy resins are often used in electrical applications, including the encapsulation of computer semiconductor chips. One advantage of epoxy resins produced using the claimed process conditions is that they contain lower levels of hydrolyzable halide. Residual halides and other contaminants produced during the epoxidation process are sometimes responsible for computer chip failure. Thus, epoxy resins containing lower levels of hydrolyzable halide are more suitable for encapsulating semiconductor chips, and for use with other electrical applications. At issue in this appeal is the construction of the improvement process conditions as disclosed in claim 1 of the '255 patent.
B. The '255 Patent Claims
Claim 1 of the '255 patent is the only independent claim at issue on appeal. This claim is written in Jepson format, meaning that the claim first describes the scope of the prior art and then claims an improvement over the prior art. The claim reads as follows:
In a method for preparing glycidyl derivatives of compounds having at least one aromatic hydroxyl group or aromatic amine group per molecule by reacting at least one compound having at least one aromatic hydroxyl group or aromatic amine group per molecule with an excess of at least one epihalohydrin in the presence of an alkali metal hydroxide and subsequently recovering the glycidyl derivative product; the improvement which comprises
(1) conducting the reaction in the presence of an organic solvent which codistills with water and said epihalohydrin at a boiling point below the boiling point of the lowest boiling compound among the components in the reaction mixture;
(2) conducting the reaction under a reduced pressure sufficient to provide a distillate with a boiling point of from about 45 C. to about 80 C.;
(3) employing said alkali metal hydroxide as an aqueous solution and adding said aqueous alkali metal hydroxide in a continuous or intermittent manner over a period of from about 0.5 to about 10 hours;
(4) continuously removing water by means of codistillation at a rate such that the water content in the reaction mixture is less than about 6 percent by weight;
(5) separating the water from the codistillate and returning the solvent and epihalohydrin to the reaction mixture.
'255 patent, col. 11, ll. 8-26 (emphases added).
C. The Accused Sumitomo Process
Dow asserts that two processes used by Sumitomo infringe claim 1 of the '255 patent. Since 1983, Sumitomo has used two different processes to produce certain high-purity epoxy resins. The two Sumitomo processes are referred to as the "Old DOX" and the "New DOX" processes. Sumitomo used the Old DOX process from 1983 until 1996, and has used the New DOX process since 1996. Both the Old and New DOX processes conduct the well known epoxidation reaction under certain process conditions. Both processes react orthocresol novolac ("novolac") with epichlorohydrin in the presence of the solvent dioxane.1 Both the Old and New DOX processes are conducted in two stages.
In the New DOX process, the first stage commences with the addition of potassium hydroxide ("KOH") for one hour. The first hour is conducted without distillation, at atmospheric pressure, and without the removal of water. After the first hour, the first stage of the New DOX process is continued for three hours without the addition of KOH. During this three-hour period, water is removed by codistillation, pressure is maintained at 60 Torr, and the water content is maintained at 0.8 to 1.0 percent by weight.2 Throughout the entire first stage of the New DOX process, the reaction temperature is maintained at 39 ± 1 C. By the end of the first stage of the New DOX process, the epoxidation reaction is approximately sixty percent complete.
During the second epoxidation stage of the New DOX process, aqueous sodium hydroxide ("NaOH") is added to the reaction mixture for three hours.3 Throughout the second stage of the New DOX process, the reaction temperature is maintained at 62.5 ± 1 C, and the reaction pressure is maintained at 150 Torr. During this three-hour period, the mixture of water, dioxane, and epichlorohydrin is codistilled such that the water content is maintained at 0.8 to 1.0 percent by weight.
In the Old DOX process, the first stage commences with the codistillation of water, dioxane, and epi upon the initial addition of aqueous KOH. The first hour is conducted with the addition of KOH and simultaneous codistillation. After the first hour, the first stage of the Old DOX process continues for three hours without the addition of KOH. During this three-hour period, pressure is maintained at 60 Torr, and the water content is maintained at 0.8 to 1.0 percent by weight. Throughout the entire first stage of the Old DOX process, the reaction temperature is maintained at 39 ± 1 C. By the end of the first stage of the Old DOX process, the epoxidation reaction is approximately fifty- five percent complete. The second stage of the Old DOX process is identical to that of the New DOX process, except that the addition of NaOH is performed over a three and one-half hour period instead of a three-hour period.
D. Procedural Background
On January 21, 2000, the district court issued its claim construction order in which it construed a number of disputed terms used in claim 1 of the '255 patent. Dow Chem. Co. v. Sumitomo Chem. Co., No. 96-10330, slip. op. at 34, 44 (E.D. Mich. Jan. 21, 2000). Specifically, the district court construed the phrases "boiling point" as used in clause 1 and the terms "continuous" and "continuously" as used in clauses 3 and 4. Id. Dow subsequently asked the district court to clarify its construction of "boiling point" and "continuous/continuously." On April 19, 2000, the district court issued a supplemental claim construction order clarifying its construction of these phrases. Dow Chem. Co. v. Sumitomo Chem. Co., No. 96-10330, slip. op. at 13, 20 (E.D. Mich. Apr. 19, 2000).
The district court initially construed "boiling point" as used in clause 1 of claim 1 to mean that:
Codistillation must occur at a boiling point of the reaction mixture which is below the boiling point of any components of the reaction mixture, at the reaction pressure.
Dow, No. 96-10330, slip. op. at 34 (Jan. 21, 2000). In construing this limitation, the district court rejected Dow's contention that clause 1 simply requires that the codistillate "boil off" before any of the components of the reaction mixture. In the supplemental claim construction order, the district court further construed the limitation to require that "the boiling point temperature [of the codistillate be] measured in the reaction mixture" and not in the vapor phase.4 Dow, No. 96-10330, slip. op. at 13 (Apr. 19, 2000).
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