Digest of Akzo Nobel Coatings, Inc. v. Dow Chemical Company, Nos. 2015-1331, 2015-1389 (Fed. Cir. Jan. 29, 2016) (precedential). On appeal from D. Del. Before Lourie, Reyna, and Chen.

Procedural Posture: Patentee Akzo Nobel Coatings, Inc. appealed the District Court’s grant of summary judgment of noninfringement of U.S. Patent No. 6,767,956 by Dow Chemical Company. Dow cross-appealed from the District Court’s determination that the claims of the ‘956 patent are not indefinite. CAFC affirmed in both appeals.

  • Claim Construction: The District Court did not err in narrowly construing the term “pressurized collection vessel” to mean “tubing, piping, or other container where a desired material accumulates, which is maintained above atmospheric pressure.” The District Court’s construction gives the term “collection” proper meaning in light of the claim language and the specification.
  • Infringement – Literal Infringement: The District Court did not err in granting summary judgment of literal noninfringement. CAFC agreed with Dow that its accused process lacks a “pressurized collection vessel” as construed, because Akzo did not provide sufficient evidence from which a reasonable jury could find accumulation.
  •  Infringement – Doctrine of Equivalents: The District Court did not err in granting summary judgment of noninfringement under the doctrine of equivalents. Akzo failed to show that the accused Dow process had a valve and a series of pipes and heat exchanges, wherein the dispersion flows continuously, generates backpressure in the extruder in substantially the same way to increase the boiling point of the carrier fluid. Accordingly, Akzo failed to provide evidence from which a reasonable jury could find that Dow’s valve, pipes, and heat exchangers operate in substantially the same way as the claimed “pressurized collection vessel” to generate backpressure in the extruder.
  • Indefiniteness: The District Court did not err in finding that the terms “viscosity below 10 Pa.s” and “carried out at a temperature of from 5 to 150° C above the melting point of the polymer” were not indefinite.
    • “viscosity below 10 Pa.s”: The District Court correctly found, based on extrinsic evidence, that one of skill in the art would measure viscosity at room temperature in the absence of a specified temperature. Moreover, the intrinsic record supports the District Court’s determination. While neither the claim language nor the specification indicates a temperature for the final viscosity measurement, room temperature is the only temperature mentioned in the ’956 patent in connection with a viscosity measurement. Accordingly, CAFC affirmed the District Court’s conclusion that the expression “viscosity below 10 Pa.s” does not render the claims indefinite, as well as its construction of that limitation as “viscosity below 10 Pa.s at room temperature.”
    • The District Court did not err in finding that because the specification describes a typical process where the polymer “is melted in the initial melt zone of the extruder at a temperature above the melting point of the polymer, preferably from 5 to 150° C, typically 10 to 130° C, above the melting point,” the specification supports a construction which indicates that the limitation refers to the elevated temperature phases and not to the stages that follow. Further, Dow did not provide any evidence to show that a person of ordinary skill in the art would not know with reasonable certainty the steps to which the limitation applies.