CAFC: Lack of Diligence Does Not Convert PTO Error Into An Applicant Error

E.I. DuPont v. MacDermid Printing Solutions (2007-1568), May 14, 2008

When DuPont asserted its patent and sought a preliminary injunction, MacDermid countered that the patent was invalid for public use prior to the 102(b) critical date. While DuPont initially conceded the critical date, a closer examination discovered that the patent stemmed from a provisional application that was listed in the application, but priority was not properly claimed due to a PTO oversight. DuPont successfully petitioned for correction, and continued with the litigation.

MacDermid argued that DuPont was not entitled to the provisional application because (1) the non-provisional application names inventors not named in the provisional application; (2) DuPont did not use the “proper language” in claiming priority to the provisional; (3) the filing receipt, published application, and issued patent did not reference the provisional, showing that the PTO did not recognize priority to the provisional; (4) DuPont did not alert the PTO that the priority information was missing until the patent issued; and (5) the Certificate of Correction that added the priority information was wrongly issued. MacDermid also argued that it would be unfairly prejudiced by DuPont’s change of position.

The district court found it could not grant a preliminary injunction on the record because DuPont did not sufficiently prove it was entitled to the earlier critical date, and that DuPont's earlier admission as to the later critical date raised a substantial question as to validity.

On appeal, the CAFC found that the lower court abused its discretion on the issue of priority. It was particularly significant that, while priority wasn't formally claimed, the Application Data Sheet on the non-provisional application identified priority to the provisional application. Noted the court, "[s]ince MacDermid admittedly was aware of the provisional application, it is difficult to see how MacDermid would be prejudiced by its consideration in evaluating validity."

With regard to the other issues, the CAFC found that the provisional application shared one common inventor (see MPEP 201.03), had supporting disclosure under section 112, and was filed less than one year before the nonprovisional application. Accordingly:

The only issue is the legal significance of these facts, i.e. whether the non-provisional application is entitled to claim the priority date of the provisional application. Determination of the priority date (e.g., the effective filing date) is purely a question of law if the facts underlying that determination are undisputed . . . it is unclear what necessary evidence the district court thought was missing from the preliminary injunction record.

With regard to DuPont not using the "magic"(i.e. PTO-approved) language for priority,

Here, rather than the precise language suggested in the MPEP, the ADS in the non-provisional application stated: “Continuity Data: This application is a non-provisional of provisional 60/273669 2001-03-06 WHICH IS PENDING.” Contrary to MacDermid’s argument, this reference did not run afoul of the MPEP by failing to use magic words. The MPEP provision requires only that the applicant use a statement “such as” the one provided in Section 201.11. A reasonable person reading the language in the ADS would have concluded that the applicant was claiming priority to an earlier provisional application. Thus, we find no defect in the language used to reference the provisional application here.

And with regard to the certificate of correction:

By putting the continuity data in the ADS, DuPont expected that the PTO would capture the information and place it on the title page of its patent. As MacDermid notes, however, there were some indications during prosecution that the PTO had failed to capture the information. MPEP § 201.11. We hold that a lack of diligence during prosecution, at least under the facts of this case, does not convert a PTO error into an applicant error for the purpose of seeking a post-issuance certificate of correction.

VACATED AND REMANDED