Navigating Unexpected Results: PTAB Decision Outlines Key Requirements for Rule 132 Declarations

by Dennis Crouch

In a recent decision, the PTAB affirmed an examiner’s obviousness rejection of claims related to an anodizing process for aluminum and magnesium alloys. Ex parte Eidschun, Appeal 2023-003437 (PTAB Oct. 16, 2024). The case offers an example of a R132 declaration from the inventors that was deemed insufficient to provide evidence of unexpected results in order to rebut obviousness arguments.  To be more precise, the declaration appears to have overcome the examiner’s obviousness rejection, but the Board provided new reasoning (based on the same references) and so sustained the rejection based upon these new grounds.

The Technology: The application claims a method for controlling dimensional growth during the anodizing of aluminum or magnesium alloys. This result is important because it allows for more precise manufacturing of parts, eliminating the need to account for size changes during the anodizing process and potentially reducing waste and rework.

The process involves an anodizing solution that has two key components:

  1. An acid solution (10-20% w/v) selected from sulfuric, nitric …; and
  2. An oxidizing agent (0.01-0.05% w/v) selected from potassium permanganate, sodium permanganate, ….

The examiner rejected the claims as obvious over a combination of prior art references, primarily relying on Windsor-Bowen (GB 396,743, 1933) in view of Haga (JP-H0774055-A, 1995) and other secondary references.

In the appeal, the patentee relied upon a Rule 132 Declaration by the inventors, Keith Eidschun and Joshua Cloakey. The declaration attempted to show unexpected results compared to both the prior art (Windsor-Bowen) and conventional anodizing processes.

Despite the declaration, the PTAB affirmed the examiner’s rejection but on slightly different grounds.  Rather than Windsor-Bowen in view of Haga; the Board flipped and found the proper rejection relied upon Haga in view of Windsor-Bowen.  The Board found that Haga disclosed most of the claimed elements, including the acid concentration range. Haga also mentioned using potassium permanganate as an oxidizing agent but did not specify its concentration. The Board then looked to Windsor-Bowen, which taught using 1% or less of an oxidizing agent (albeit a different one) in a similar anodizing process.

The PTAB reasoned that one of ordinary skill would have had a reasonable expectation of success in applying Windsor-Bowen’s oxidizing agent concentration to Haga’s potassium permanganate oxidizing agent.  I’ll note here that this conclusion is somewhat unbelievable – recognizing that the upper limit of the claimed range (0.05%) is 20-fold less than that (1%) disclosed in Windsor-Bowen, but the PTAB concluded with mathematic precision that the disclosed range of “1% or less” from Windsor-Bowen to encompass the claimed range of 0.01% to 0.05%.

Focusing-in on the declaration, the PTAB noted several deficiencies:

1. Failure to compare with the closest prior art: The declaration focused on distinguishing Windsor-Bowen, which – based upon the new grounds of rejection – was not the closest prior art.  In several prior cases, the Federal Circuit has affirmed that “unexpected results” must be with reference to the closest prior art. In re Baxter Travenol Labs., 952 F.2d 388, 392 (Fed. Cir. 1991) (“when unexpected results are used as evidence of nonobviousness, the results must be shown to be unexpected compared with the closest prior art”).

2. Lack of evidence of unexpectedness: The PTAB also explained that simply showing a difference in results is not enough; the difference must be shown to be unexpected. In re Freeman, 474 F.2d 1318 (CCPA 1973) (explaining that there must be (1) an actual difference; and (2) that difference would not have been expected).  Here, conclusory statements from the inventors themselves that the differences were “unexpected” is not sufficient.

3. Results not commensurate in scope with the claims: Finally, the evidence presented needs to be commensurate in scope with the claims. The PTAB noted here that the applicant’s independent claim encompassed eight acids and five oxidizing agents (alone or in combinations), but the data only included one acid (sulfuric) and one oxidizing agent (potassium permanganate).  Similarly, the oxidizing agent used was near the top of the range (0.05%) and did not show results at the lower end (0.01%). This potentially cherry-picked data may show that certain embodiments of the claims are unexpected, but not necessarily that the entire scope is unexpected.  The problem here of course, is that a providing experimental data in this situation will be quite expensive.

New Ground of Rejection: Because of its changed reasoning, the PTAB designated this case as a new ground for rejection – providing the applicant with additional opportunities to make its case.

When the PTAB issues a new ground of rejection under 37 CFR 41.50(b), the appellant has three options: (1) reopen prosecution before the examiner by submitting an appropriate amendment and/or new evidence within 2 months of the Board’s decision; (2) request a rehearing before the Board within 2 months; or (3) file a request for continued examination (RCE). If the appellant chooses to reopen prosecution, they can amend the rejected claims or submit new evidence related to those claims. The examiner will then reconsider the rejection in light of the changes. If the appellant requests a rehearing, they waive their right to further prosecution before the examiner, except for the limited right to rewrite dependent claims not subject to the new grounds into independent form.  I expect that in this case the applicant will reopen prosecution and submit additional evidence that uses the roadmap set out in this decision.  They may also narrow some claims to ensure that their experimental data fits more properly to the claim scope.  The submission may also want to focus in on the difference in the prior art range of “1% or less” as compared with the claimed range of 0.01% to 0.05% — experimental evidence would likely show a wide difference in results based upon the concentration used within this range.

Declarations from experts, including the inventors, can be incredibly powerful to move prosecution forward.  The decision here highlights some of the difficulties when ensuring that they serve the looked-for goals.