The CAFC considers oxidation in Zhejiang v. Kaneka

The bottom line:


Under the proper construction, even without consideration
of Dr. Sherman’s opinions, we conclude there is a
dispute of material fact regarding whether ZMC’s processes
meet the “oxidizing” limitation in claims 22 and 33.
The district court erred in granting ZMC’s motion for
summary judgment of noninfringement.



The dispute:


At the outset, Kaneka argues the district court “improperly
changed” our construction of “oxidizing” in
Kingdomway from “some action resulting in oxidation” to
an action that increases the amount of oxidation above a
baseline of passive oxidation. It argues the district court’s
changed construction led it to erroneously exclude
Dr. Sherman’s expert report and grant summary judgment
of noninfringement. We agree in part.

In Kingdomway, we held “oxidation requires an active
step.” 790 F.3d at 1305.

(...)
The district court interpreted our construction to
mean “some amount of oxidation, in excess of that which
occurs naturally from exposure to ambient air, must be
caused by an ‘active step’ in the coenzyme Q10 manufacturing
process.” J.A. 48 (emphasis added). This is not
precise. The only bounds provided by Kingdomway on
what constitutes an “active step” or “active oxidation” is
that it does not require use of an oxidizing agent. 790
F.3d at 1306. The opinion emphasizes that there must be
“some action resulting in oxidation”; the oxidizing step
“cannot be interpreted as doing nothing, or to simply
allow oxidation to occur on its own.” Id. at 1305–06
(emphasis added). But the opinion does not state that to
be an active step, the oxidation rate must be greater than
that of passive oxidation. And it is silent as to any degree
of oxidation that would be necessary to qualify as active
oxidation. The opinion simply requires that there be
some action that results in oxidation. Id. at 1307.



Observe footnote 2:


The question whether the term “oxidizing” requires
an oxidizing agent was before the prior panel of
this court, and we are bound by their decision that it does
not. See id. Thus, it is not a decision that we can review.