Federal Circuit affirmed DC claim construction finding that “100% by weight” limitation can include “residual moisture”

E.I. Du Pont De Nemours & Co. v. Unifrax I LLC

Docket 2017-2575
April 17, 2019

Brief summary: DC finding that “platelets in an amount of 100% by weight” can include “some residual dispersant” and its denial of JMOL based on jury findings of no infringement or anticipation, affirmed.

Summary: Unifrax appealed DC claim construction and denial of its motions for judgment (JMOL following jury decisions) of non-infringement and invalidity of Du Pont’s (DP’s) US 8,607,926 relating to composite laminates incorporated into thermal-acoustic blankets in airplanes. The DC agreed with DP that “100% by weight” in the “comprises platelets in an amount of 100% by weight…and a residual moisture content of no greater than 10 percent by weight” limitation means ‘[t]here is no carrier material…in addition to the inorganic platelets” but that “[t]here may be some residual dispersant”, relying on the ‘926 specification (and its parent ‘027 patent) and prosecution history for support. The DC found that although the 100% limitation was introduced in response to a prior art rejection and DP “did not dispute that this resulted in disclaimer of at least ‘embodiments comprising an inorganic refractory layer containing platelets in an amount less than 100% by weight’”, DP did not disclaim “refractory layers that contain anything at all other than platelets” (e.g., the claims also specified “a residual moisture content”) and “the disclaimer limited the scope of the claimed layers to those containing no carrier material such as a resin or an adhesive”. The FC panel reviewed the DC’s “ultimate determination on claim construction de novo” and “any underlying factual findings related to extrinsic evidence…for clear error” (CardSoft, FC 2015; Markman, US 1996; Phillips, FC 2005; Medrad, FC 2005; Microsoft, FC 2004 (“when the specification ‘makes clear that the invention does not include a particular feature, that feature is deemed outside the reach of the claims” even if those “might be considered broad enough to encompass the feature in question”)). The FC agreed with the DC’s based on the claim’s plain language (e.g., “reference to both ‘100% by weight’ platelets and 10% residual moisture”), the specification (e.g., “‘100% by weight’ is relative to the carrier material in the refractory layer” as it states that “[t]he refractory layer may comprise some residual dispersant.”) and the prosecution history (patentee “understood the claimed language to be relative to carrier material”). The FC panel also found the DC’s consideration of the parent ‘027 patent specification in its claim construction analysis was proper (Wang Labs., FC 1999; Jonsson, FC 1990; Advanced Cardiovascular, FC 2001 (which the FC panel read not to require “the exact claim term at issue” be present in both patents)). The FC panel also found “the jury’s infringement verdict” and no anticipation to be supported by substantial evidence. And under the “‘rule of reason’ analysis”, the FC panel concluded “that the corroborative evidence” of conception and reduction to practice supported “the credibility of” the inventors’ “story”, and therefore the ‘926 patent was entitled to its claimed priority (i.e., prior to the first public use date (NFC, FC 2003)). Thus, the DC’s decision was affirmed. Judge O’Malley’s dissent argued that the claim construction was erroneous and “introduces more ambiguity than it resolves” (e.g., “The ‘100% by weight’ language, coupled with the requirement that the platelets exist in an ‘inorganic refractory layer,’ clearly contemplates that the platelets-i.e., inorganic material-constitute the entirety of the refractory layer.”)

This entry was posted in Anticipation (35 USC 102), Claim Construction, Conception and Reduction to Practice, Infringement. Bookmark the permalink.

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