Ex parte Maeda is a 2009 decision of the Board of Patent Appeals and Interferences (BPAI) that is listed among the Patent Trial and Appeal Board’s (PTAB) informative decisions. Ex parte Maeda is indicated by the PTAB to be informative as to “proof properties are not inherent.”
According to the PTAB’s Standard Operating Procedure, “[i]nformative decisions set forth Board norms that should be followed in most cases, absent justification, although an informative decision is not binding authority on the Board.”
In Ex parte Maeda, the BPAI considered whether the experimental results in a patent applicant’s specification were sufficient to rebut an examiner’s assertion that applicant’s claimed composition was inherently anticipated by a prior art composition.
An illustrative claim recited:
An active material for a positive electrode of a lithium secondary battery, comprising a lithium-nickel composite oxide of the general formula Lix(Ni1-yCoy)1-zMzO2; where 0.98 ≤ x ≤ 1.10; 0.05 ≤ y ≤ 0.4; 0.01 ≤ z ≤ 0.2; and M is chosen from at least one element selected from the group of Al, Zn, Ti, and Mg; wherein
a. according to Rietveld analysis, the Li site occupancy rate for Li sites in a crystal of the lithium-nickel composite oxide is 98% or greater;
b. the average particle size of spherical secondary particles of the lithium-nickel composite oxide ranges from 5 pm to 15 pm; and
c. when the active material is subjected to a washing process, the difference between the specific surface area of the active material before the washing process and after the washing process is 1.07 m2/g or less.
The examiner rejected the claim as anticipated by a prior art patent publication. It was undisputed that the prior art disclosed an active material satisfying the compositional requirements of the claim. However, applicant argued that the examiner had failed to establish that the prior art composition inherently possessed the Li site occupancy rate (feature (a)) and difference in specific surface area after washing (feature (c)) of the claim.
Applicant pointed to the examples and comparative examples of its own specification, which included active materials satisfying the compositional requirements of the claim. Among those active materials, some possessed feature (a) and feature (c), and some did not. Thus, applicant argued, it was not possible for the examiner to conclude that the prior art composition necessarily possessed feature (a) and feature (c) of the claim simply because the prior art composition satisfied the compositional requirements.
The BPAI rejected this argument. First the BPAI stated that, by demonstrating the prior art composition satisfied the compositional requirements of the claim, the examiner properly shifted the burden to applicant to prove that the prior art composition did not, in fact, possess feature (a) and feature (c). While some of applicant’s comparative examples satisfied the compositional requirements of the claim but did not possess feature (a) and feature (c), this was not proof that the different prior art composition also did not possess feature (a) and feature (c).
In affirming the examiner’s rejection, the BPAI noted particularly that none of the comparative examples of applicant’s specification were alleged to correspond to the prior art active material and, further, applicant did not allege that its comparative examples represented the closest prior art.
Interestingly, Ex parte Maeda was decided by an expanded five-judge panel, instead of the usual three-judge panel. Two Vice Chief Administrative Judges are identified among the deciding judges. According to the PTAB’s Standard Operating Procedure, “[a]n expanded panel is not favored and ordinarily will not be used… [a]n expanded panel may be used, where appropriate, to secure and maintain uniformity of the Board’s decisions…”
Takeaway: When trying to persuade an examiner that a property of a claimed composition is not inherent in a prior art composition, it is preferable to avoid the time and expense of reproducing and testing the prior art composition. Many applications, like the application in Ex parte Maeda, already include examples and comparative examples showing that not all compositions having the claimed compositional requirements possess the claimed properties. To persuade an examiner based on such examples and comparative examples, it is important to take the extra step of providing a compelling rationale for why the comparative examples are illustrative or more similar to the claimed composition than the prior art composition.
Judges: Moore, MacDonald, Smith, Gaudette, Colaianni
by Jacob Doughty
Jacob A. Doughty is a patent attorney and founding partner of Element IP. Jacob’s practice includes all areas of US patent law with an emphasis on patent prosecution and management, client counseling, opinion work, and due diligence in the chemical, pharmaceutical, and biotechnology sectors.