On January 29, 2016, the United States Court of Appeals issued a decision in Akzo Nobel Coatings, Inc. v. Dow Chemical Company, relating to an appeal from the United States District Court for the District of Delaware. The opinion of the panel was delivered by Judge Alan Lourie, who was joined by Judge Jimmie Reyna and Judge Raymond Chen.
Akzo appealed from the decision of the district court (Chief Judge Leonard Stark) to grant summary judgment to Dow, which found that Dow did not infringe the claims of U.S. Patent 6,767,956, either literally or under the doctrine of equivalents. Dow also cross-appealed from the district court’s conclusion that the claims of the ’956 patent were not indefinite. Ultimately, the Federal Circuit affirmed the district court on both appeals.
Claim 1 of the ‘956 patent was deemed representative and reads as follows:
1. A process for producing a dispersion of a polymer in an aqueous medium in which the polymer is dispersed in an aqueous medium in an extruder at a temperature above 100° C. in an extruder having an outlet
wherein the pressure in the extruder is maintained above atmospheric so that the aqueous medium does not boil characterized by maintaining the pressure above atmospheric for the extruder at the outlet with a pressurized collection vessel and
wherein aqueous dispersion from the extruder has at least 25% by weight of the aqueous medium where the aqueous medium has less than 40% by weight of organic solvent and
wherein the aqueous dispersion enters the outlet and pressurized collection vessel at a pressure above atmospheric so that the aqueous medium does not boil and is subjected to the action of a cooling zone to lower the temperature of the aqueous dispersion to below 100° C. to have an aqueous dispersion with a viscosity below 10 Pa.s.
Claim 2 further requires: “[a] process according to claim 1 which is carried out at a temperature of from about 5 to 150° C. above the melting point of the polymer.”
In October 2012, Akzo sued Dow for patent infringement, alleging that Dow’s BLUEWAVE™ process infringed claims 1–8 of the ’956 patent. Because Dow believed Akzo failed to identify any “pressurized collection vessel” in the accused process, Dow sought leave of court to file an early summary judgment motion of non-infringement, which was granted. This lead to a combined summary judgment and Markman hearing.
After construing the claims, the district court granted Dow’s motion for summary judgment of non-infringement. In describing Dow’s accused process, the court found that “Dow’s accused process uses a valve and allows the polymer dispersion to flow continuously. It does not accumulate.” That lack of accumulation precluded a finding of either literal infringement or infringement under the doctrine of equivalents.
The Federal Circuit affirmed the district court’s claim construction and also agreed with Dow (and the district court) that Akzo failed to raise a genuine issue of material fact as to literal infringement, and thus affirmed the district court’s grant of summary judgment of no literal infringement. Similarly, although infringement under the doctrine of equivalents is a question of fact, equivalency must be established on a limitation by limitation basis and linking the insubstantiality of the differences between the claimed invention and the accused device or process. Ultimately, the Federal Circuit concluded that Akzo failed to establish a genuine issue of material fact as to whether Dow’s process operates in substantially the same way. Indeed, the Federal Circuit explained that Akzo offered only ambiguous generalities on the critical issue of whether the generation of backpressure in the extruder to increase the boiling point was achieved in substantially the same way.
On cross-appeal, Dow challenged the district court’s conclusion that the claims of the ’956 patent are not invalid for indefiniteness. Specifically, Dow contested two limitations. First, Dow argues that “viscosity below 10 Pa.s” renders the claims indefinite because it fails to recite the temperature at which the viscosity measurement is to be taken. Second, Dow argues that “carried out at a temperature of from 5 to 150° C. above the melting point of the polymer” renders the claims indefinite because it fails to specify which steps in the claimed process occur at those elevated temperatures.
The Federal Circuit found Dow’s arguments relating to indefiniteness unpersuasive and affirmed the district court. On the first issue, the Federal Circuit found evidence to support the district court that one of skill in the art would measure the viscosity at room temperature in the absence of a specified temperature. On the second issue, the Federal Circuit found the specification included sufficient support to make the language sufficiently definite when considered by one of skill in the art.