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April 15, 2022by Yanhong Hu

Functional equivalence is a rationale that examiners often rely on in support of an obviousness rejection. However, as discussed in one of our previous blogs, examiners may misapply the rationale by ignoring the different function or purpose of an allegedly equivalent component disclosed in prior art. A recent decision of the Patent Trial and Appeal Board (“Board”) – Ex parte Takasu (Appeal 2021-001290) – is another illustrative case.

Appellant’s claimed invention in Takasu was a substrate of a single crystal of formula RAMO4, where, among other things, R could be Sc, A could be Al, and M could be Mg. The claimed RAMO4 substrate had an epitaxially-grown surface and a satin-finish surface, each having specific surface roughness.

Yoshii, the primary reference relied on by the Examiner, provided a sapphire substrate for epitaxial growth that could be easily polished. The Examiner found that Yoshii as evidenced by Hansen disclosed a sapphire single crystal substrate that allegedly had the claimed roughness on its front and back sides. The Examiner admitted that the sapphire substrate disclosed in Yoshii was not a RAMO4 substrate. However, the Examiner found a secondary reference, Yoshida, which disclosed ScAlMgO4 as one of the material options for a single crystalline substrate as a functional equivalent to sapphire for epitaxial growth. The Examiner thus concluded Appellant’s claimed RAMO4 substrate would have been obvious over Yoshii in view of Yoshida as evidence by Hansen.

Appellant argued that a sapphire substrate and a RAMO4 substrate were not equivalent to each other in terms of surface polishing properties.

The Board agreed with Appellant and emphasized that, as stated by the Examiner herself, Yoshida merely disclosed ScAlMgO4 as “a functional equivalent to sapphire for epitaxial growth, but … not for surface polishing properties.”

Because a sapphire substrate is not functionally equivalent to a RAMO4 substrate in terms of surface polishing properties, the Board found that the Examiner’s reliance upon Yoshida was misplaced and reversed the obviousness rejection.

Takeaway:  As cautioned in MPEP § 2144.06 II, the equivalency of a proper substituting equivalent must be recognized in the prior art for the same purpose and cannot be based on applicant’s disclosure or the mere fact that the components at issue are functional or mechanical equivalents. Thus, arguments rebutting an examiner’s obviousness rejection relying on functional equivalence may be successfully advanced by carefully analyzing the function and purpose of substituted and substituting components disclosed in prior art.

Judges:  J. T. Smith, B. A. Franklin, and J. R. Snay


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April 1, 2022by Jacob Doughty

Ex parte Nakanishi, is a recent decision of the Patent Trial and Appeal Board (PTAB) addressing obviousness of a claim directed to a steel composition.

The claim at issue recited, in part:

A non-oriented electrical steel sheet having a chemical composition consisting of, in mass%…

Si: 1.0% or more and 4.0% or less;

Mn: 0.10% or more and 3.0% or less…

Al: less than 0.0005%;

Cu: 0.02% or more and less than 0.04%; and

Ca: 0.003% or more and 0.0100% or less…

In asserting obviousness, the examiner cited a single prior art reference disclosing a steel sheet including components and amounts that could overlap with those recited in the claim. Applicant’s arguments focused first on differences between the claimed composition and the prior art composition and then on evidence of unexpected results.

Applicant’s arguments as to composition focused particularly on the amounts of Al, Cu, and Ca in the claims and the prior art reference. Notably, applicant’s ranges of amounts of Al, Cu, and Ca were much narrower than those in the prior art reference.

Component Claim Prior Art Reference
Al Al < 0.0005% Al ≤ 3%
Cu 0.02% ≤ Cu < 0.04% Cu ≤ 5%
Ca 0.003% ≤ Ca  ≤ 0.0100% (total content of Mo, W, Sn, Sb, Mg, Ca, Ce, and Co trace elements) ≤ 0.5%

Applicant first argued that the prior art reference did not disclose a single example composition having the claimed amounts of Al, Cu, and Ca. The PTAB quickly dismissed this argument, noting that the prior art reference was “not limited to its examples.”

Next applicant argued that the prior art reference did not recognize that the amounts of Al, Cu, and Ca were result effective and undue experimentation would have been required to arrive at the claimed narrow ranges. The PTAB replied that the prior art reference would have suggested to a skilled artisan that “all Al, Cu, and total trace element amounts within the disclosed ranges are effective for achieving” the goal of the prior art reference, “a non-oriented magnetic steel sheet whose core loss in a high frequency range can be fully reduced… including amounts within the… [claimed] ranges.”

Applicant then turned to its experimental results. Applicant argued that its experimental results showed that adding Ca in the claimed amounts to a steel sheet containing ultra-low amounts of Al unexpectedly reduces iron loss.

The PTAB noted that applicant’s experimental results were limited to compositions having a Si content of 1.3% and 1.6 % and an Mn content of 0.5%, while the claim encompassed Si contents as high as 4.0% and Mn contents as high as 3.0%. The PTAB then noted a statement in applicant’s specification that Si and Mn have the effect of reducing iron loss (the same effect applicant attributed to addition of Ca in describing its experimental results). In view of this statement, the PTAB concluded that applicant would have to provide evidence that its experimental results were representative of compositions including the minimum claimed amount of Ca and the maximum claimed amounts of Si and Mn, to effectively rebut the examiner’s assertion of obviousness.

Takeaway: Once an examiner has established that a prior art range overlaps with a claimed range, it will be difficult to persuade the examiner (or PTAB) that selection of a subrange would not have been obvious in the absence of evidence of unexpected results – in this case, the PTAB seemed annoyed that applicant even tried. It may be preferable to leave out arguments that will never succeed (e.g., the claimed composition is not exemplified in the prior art reference) and emphasize the results that might succeed (unexpected results).

A composition claim with many components, each with its own range of amounts, can make it difficult to prove that evidence of unexpected results is “commensurate in scope” with the claim. In this case, applicant showed a desirable effect over the entire range of amounts of the component it believed was important (Ca amount), provided a limited number of data points for the other components. It is often not practical to prepare a large number of compositions encompassed by a claim, but this can be addressed with a technical explanation for why additional experiments would not be expected to yield significantly different results (even more helpful if such explanation is provided in a declaration by a skilled artisan).

Judges: Owens, McGee, Inglese


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March 24, 2022by Beau Burton
Obviousness rejections of composition claims are often premised on an examiner’s assertion that it would have been obvious to replace a component in a primary reference composition with a functionally equivalent component from a secondary reference. As discussed in a prior blog, the context of a disclosure of functional equivalence is key because obviousness requires an examiner to show a skilled artisan would have had an apparent reason to modify the prior art to arrive at the claimed invention. And when a component is taught to be an alternative for a completely different purpose, this undercuts the apparent reason to modify the prior art. Ex parte Shooshtari is illustrative.

The claims on appeal in Shooshtari were drawn to a binder composition that included “a catalyst for catalyzing a crosslinking reaction between the reducing sugar and the crosslinking agent, wherein the catalyst comprises a sulfonic acid compound.” The primary reference relied on by the Examiner disclosed a binder composition that included a pH adjuster, such as HCl, for preventing unwanted polymerization, but it did not disclose the presence of a sulfonic acid compound.

To remedy this deficiency the Examiner relied on a secondary reference that taught a binder composition containing a mineral acid catalyst, such as HCl or p-toluene sulfonic acid, to effect crosslinking reactions. According to the Examiner, it would have been obvious to replace the HCl pH adjuster of the primary reference with the sulfonic acid polymerization catalyst of the secondary reference. The Board disagreed.

In particular, the Board found that the primary reference taught HCl for the sole purpose of adjusting the pH to inhibit unwanted polymerization, while the secondary reference taught HCl and sulfonic acid as acid catalysts to effect crosslinking reactions–a completely different purpose. Consequently, the Board held the Examiner failed to identify a reason why a skilled artisan would have sought to include the acid catalyst of the secondary reference in the composition of the primary reference.

Takeaway: Shooshtari shows the value in analyzing the purpose of each component of a composition when facing an obviousness rejection that relies on functional equivalence. The purpose and function of the components ties into whether there is an apparent reason to modify the prior art in the manner proposed by the Examiner. Here, the purpose of the components in each of the references was contradictory to the other such that a skilled artisan would not have had a reason to equate and replace them. Accordingly, when facing a rejection that relies on functional equivalence it is important to fully assess the purpose and function of the components involved.

Judges: T. Ownes, W. Wilson, J. Snay


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March 17, 2022by Beau Burton

There is no requirement to provide unexpected results until the Patent Office establishes a prima facie case of obviousness. Seems simple, but Ex parte Popplewell shows Examiners still put the cart before the horse and improperly seek evidence of unexpected results.

This initial burden for showing unpatentability falls on the patent office because § 102 mandates that “[a] person shall be entitled to a patent unless.” See In re Glaug, 283 F.3d 1335, 1338 (Fed. Cir. 2002) (the PTO “bears the initial burden of presenting a prima facie case of unpatentability… However, when a prima facie case is made, the burden shifts to the applicant to come forward with evidence and/or argument supporting patentability.”). Despite this unambiguous framework of burden shifting, Examiners routinely seek evidence of unexpected results prematurely.

In Popplewell, the independent claim required a spray dryer in a particular method to have inlet and outlet air humidity values between 0–4 and 10–20 g H2O/kg dry air, respectively. The Examiner admitted that the prior art relied on did not teach the inlet or outlet air humidity. While this should have been the end of examination, the Examiner took the position that the claimed inlet and outlet air humidities did not provide an unexpected result over the prior art.

On appeal, the Board found the Examiner’s statement regarding the claimed air humidities to be nothing more than a “mere conclusory statement[]” lacking an “articulated reasoning with some rational underpinning to support the legal conclusion of obviousness.” From the Board’s perspective, the Examiner failed to show that the prior art taught or suggested the inlet and outlet air humidities and failed to provide any explanation as to why the claimed humidities would have been obvious. Consequently, the Board held the Examiner’s request for a showing of unexpected results was inappropriate.

Takeaway: Poppelwell is a good reminder that: one, “obviousness requires a suggestion of all limitations in a claim”; and two, an Examiner’s demand for evidence of unexpected results prior to showing a suggestion of all limitations is improper. CFMT, Inc. v. Yieldup Intern. Corp., 349 F.3d 1333, 1342 (Fed. Cir. 2003). It is surprising to see a case like this on appeal because it requires the Examiner and an appeal brief review panel to misunderstand the burden shifting framework before the case is sent to the Board, but it shows why some appeals are inevitable.

Judges: G. Best, L. Ren, M. Cashion


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March 11, 2022by Yanhong Hu

Applicants can traverse rejections by submitting evidence in the form of a declaration under 37 CFR 1.132. While factual evidence, such as additional experimental data, is preferable, opinion testimony, which is often brushed off by examiners, is entitled to consideration as long as the opinion is not on the ultimate legal conclusion. A recent decision of the Patent Trial and Appeal Board (“Board”) – Ex parte Zhu (Appeal 2021-001375) – illustrates a situation where an expert’s opinion testimony provided evidence that successfully traversed the Examiner’s obviousness rejection.

Appellant’s claimed invention in Zhu was directed to an electrochemical test sensor containing a base, a lid, multiple electrodes, and a dried reagent. The dispositive issue before the Board was whether the evidence of record supported the Examiner’s finding that the primary reference (Bateson) described or suggested an electrochemical test sensor having a dried reagent that “has a uniformity in which the ratio of the thinnest point to the thickest point is greater than about 0.2” as claimed.

The Examiner admitted that Bateson did not explicitly disclose the feature but provided a hypothetical calculation based on Bateson’s disclosure, including the drawings, and obtained a ratio of 0.64 between the thinnest and thickest points.

Appellant responded with declaratory evidence from Mr. Brown (an employee of the assignee’s subsidiary company) explaining why the Examiner’s hypothetical calculation was erroneous. Mr. Brown stated that when a dry reagent was obtained from a wet reagent, “[t]he exact percentage of the reduction in the thickness would depend on the drying conditions and the crystalline or molecular structure of the dissolved solid materials in the wet reagent.” Mr. Brown further stated that “details like the contour of the dried reagent” must be considered when the ratio was calculated because the surface of the dried reagent was not smooth, citing a figure in Appellant’s application as a proof and noting that a skilled artisan would expect the dried reagent in Bateson to exhibit the “coffee ring” effect upon drying, which represented a non-uniform reagent surface.

The Examiner gave little or no weight to Mr. Brown’s statements. While noting that Bateson did not disclose the “coffee ring” effect or details pertaining to the surface contour of the wet or dried reagent, the Examiner argued that “it would be improper to read into the disclosure of Bateson to give the surface of the reagent any particular contour without some teaching, suggestion and/or evidence to do so.”

The Board, however, found that Brown’s testimony was valid evidence showing that a skilled artisan would have expected a calculation of the ratio to require details such as the contour of the surface of the reagent. Because, as acknowledged by the Examiner, Bateson did not disclose any noteworthy details regarding the surface contour of the reagent, the Board found that the record before it supported Appellant’s position that the Examiner failed to make a sufficient showing that Bateson disclosed or suggested the recited ratio.

Takeaway:  It is known to patent practitioners that arguments of counsel are not evidence and must be supported by an appropriate affidavit or declaration from an expert. The expert can be an outside expert or someone from inside the company as in Zhu as long as they have appropriate expertise. While an opinion affidavit or declaration which states only conclusions may have little probative value, weight and deference should be given to factually supported statements and, particularly, to the underlying factual basis, as illustrated by Zhu.

Judges:  M. N. Ankenbrand, B. D. Range, and L. Ren


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March 4, 2022by Matthew Barnet

In Ex parte Abbott (Appeal No. 2021-000770), the examiner rejected the claims as obvious based on an optimization rationale. The PTAB reversed.

Independent claim 1 recited a lighting device for an additive manufacturing machine (i.e., a 3D printer). The device included an array of light sources configured to emit monochromatic light within a band of wavelengths. The band of wavelengths included a peak light absorption of a liquid coalescing agent, so that when the liquid coalescing agent absorbed the light, heat would be generated to melt or sinter a patterned building material.

Claim 1 recited a spectral intensity of at least 1 x 1012 W m-3 sr-1 for each of the monochromatic light sources. The dispositive issue on appeal was whether this limitation was suggested by the applied references.

The examiner acknowledged that the primary reference (Miller) did not disclose this limitation. However, the examiner cited Miller’s teaching that the “amount of radiation provided to each location on the built model should be the amount that ensures sufficient curing in that location,” and that “[t]he radiation may be of any type, or in any wavelength that causes curing of the build material.” The examiner found that a skilled artisan “would have recognized that the light sources taught by Miller could be operated to emit a desired spectral intensity.” The examiner concluded that the claimed spectral intensity could be obtained through “routine optimization of this result-effective variable to provide the intended result of curing of build material during an additive manufacturing process.”

In contrast, the applicant noted that the Miller reference taught no specific values or ranges for spectral intensity. Because of this, the applicant argued that an optimization rationale was unsupported. The applicant cautioned that if the examiner’s position were correct, then the general disclosure of Miller would be sufficient to “render obvious the use of radiation to solidify anything under any conditions for every 3D printing process no matter how specific and how novel the radiation and no matter how different the process.”

The PTAB agreed with the applicant. The PTAB found the lack of any disclosed range of spectral intensity in Miller to be “akin to a very broad range (as there is not a set limit since no limit is provided in Miller).” The PTAB found such a broad range to be “so broad that there is no invitation for routine optimization.” Accordingly, the PTAB reversed the obviousness rejection.

Takeaway: Whenever an examiner takes the position that a claimed variable is a result-effective variable that would have been obvious to optimize, it is important to carefully evaluate the teaching of the prior art relating to the claimed variable. If, as in Ex parte Abbott, there are no specific values or ranges of the claimed variable in the prior art, then the optimization rationale might lack adequate support.

Judges: Franklin, Praiss, Inglese


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February 11, 2022by Yanhong Hu

A typical Markush group is structured as “selected from the group consisting of A, B, and C.” The language is closed in nature due to the closed transitional phrase “consisting of.” However, it is not uncommon for an open-ended claim to recite a Markush group in patents or patent applications related to chemical arts. An issue that often arises , therefore, is whether unrecited members of the “closed” Markush group are allowed in open-ended claims. In Ex parte Kapitan (Appeal 2021-001272), the Patent Trial and Appeal Board (“Board”) addressed such an issue.

Appellant’s claimed invention in Kapitan was directed to a process for making a methylfluoroacrylate “comprising” steps A-D, wherein “the solvent in at least steps C and D … is an alkane selected from a group consisting of pentane and hexane.”

The Examiner rejected the claimed process as obvious over a combination of several prior art references. The Examiner admitted that the primary reference did not disclose using pentane or hexane as the solvent in making methylfluoroacrylate; and relied on a secondary reference, Sedlak ‘967, for the admitted deficiency. In particular, the Examiner found Sedlak ‘967 used inert solvent, including petroleum ether, which, according to the Examiner, “consists of pentane and hexane hydrocarbons.” However, as noted by the Board, the Examiner did not provide evidence establishing that petroleum ether was either pentane or hexane.

Appellant, on the other hand, provided several prior art references during prosecution showing that petroleum ether was not a single composition but a mixture of aliphatic hydrocarbons, such as a mixture of C5 to C13 paraffins that might contain a small amount of aromatic hydrocarbons.

The Board thus agreed with Appellant that petroleum ether had numerous variations of petroleum ether components that were not limited to pentane or hexane. The Board noted that by using the open-ended transitional phrase “comprising,” the claimed process allowed for additional steps. However, the Board further noted “that additional steps may be allowed does not mean that the solvent for use in the reaction step C as modified by the wherein clause, i.e., the alkane solvent [] being ‘selected from a group consisting of pentane and hexane,’ can be something other than pentane or hexane.” Citing Amgen, Inc. v. Amneal Pharms. LLC, 945 F.3d 1368, 1377–78 (Fed. Cir. 2020), which discussed in detail Multilayer Stretch Cling Film Holdings, Inc. v. Berry Plastics Corp., 831 F.3d 1350 (Fed. Cir. 2016), the Board concluded that, just as was the case in Multilayer, the suitable solvent required to be used in step C in Appellant’s claimed process was restricted to the listed solvents by the use of the closed Markush transition phrase “selected from the group consisting of.”

Because Sedlak ‘967’s teaching of using “petroleum ether” in its reaction scheme as an inert solvent did not indicate that pentane or hexane alone was a suitable inert solvent, the Examiner’s application of the prior art references was not sustainable.

TakeawayKapitan, like Multilayer, illustrates that without other language altering the meaning of a Markush clause, other unrecited members or mixtures of the recited members are not allowed even in an open-ended claim. Amgen illustrates a different situation. Specifically, the Amgen Court held that additional unrecited members of a Markush group and mixtures of the recited members were allowed if the Markush clause included qualifying language such as “at least one” as in “at least one selected from the group consisting of A, B, and C” and was preceded by an open-ended transitional phrase such as “comprising.” Indeed, the result would have been different if Appellant in Kapitan had recited “the solvent in at least steps C and D … comprises an alkane selected from the group consisting of pentane and hexane.”

Judges: D. E. Adams, T. Chang, and R. H. Townsend


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February 3, 2022by Beau Burton

In Ex parte Kano (Appeal No. 2021-004640), the Patent Trial and Appeal Board (“Board”) rejected an Examiner’s finding of obviousness that was premised on a nonoverlapping range being “sufficiently close.”

The independent claim on appeal was directed to a non-oriented steel having a chemical composition defined by various ranges of elements (e.g., C, Si, Mn, Al, P, S, N, etc.) and exhibiting, among other things, an X-ray diffraction (XRD) intensity ratio, I{100}/I{111}, between 0.50 and 1.18.

The primary reference relied on by the Examiner disclosed a non-oriented electrical steel sheet having a chemical composition that included each of the chemical elements in overlapping amounts, but failed to describe the intensity ratio. To remedy this deficiency, the Examiner relied on a secondary reference; however, its intensity ratio was greater than or equal to 1.20.

Notwithstanding the absence of an overlapping intensity ratio, the Examiner maintained obviousness on the basis that a steel sheet constructed from the prior art with an intensity ratio of 1.20 was sufficiently close to the claimed 1.18 ratio that one of ordinary skill in the art would expect them to have the same properties. The Board did not agree.

In particular, the applicant’s specification showed that the claimed intensity ratio resulted from a combination of the claimed composition and holding the composition at 550–700°C for 10–300 seconds (an intermediate holding step). The primary and secondary references relied on by the Examiner performed annealing processes at 950°C and 860°C, respectively, but did not include an intermediate holding step. Thus, the Board held that a skilled artisan would not have expected the steel composition from the Examiner’s hypothetical construct to have an intensity ratio within the claimed range and reversed the Examiner’s rejection.

Takeaway: While a prima facie case of obviousness may be established where the claimed range and the prior art range do not overlap, it is essential that there be an expectation that the properties would be the same. This expectation may be rebutted by information in the applicant’s own specification as in Kano or with additional experimental evidence. Another great source of rebuttal evidence is the prior art itself because a lot of times the prior art will associate its nonoverlapping range with a particular property and describe values outside that range (likely values within the claimed range) as inferior or different in some way such that a skilled artisan would not expect the properties to be the same.

Judges: J. Housel, W. Wilson, J. Gupta


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January 28, 2022by Matthew Barnet

In Ex parte Scheich (Appeal No. 2021-003495), the examiner rejected the claims as obvious over a combination of two references. The PTAB reversed.

Independent claim 1 recited:

A diffuser material of pore-containing quartz glass with

a chemical purity of at least 99.9% SiO2,

a cristobalite content of not more than 1%, and

a density in the range of 2.0 to 2.18 g/cm3,

whereby at least 80% of the pores have a maximum pore dimension of less than 20 μm,

wherein the quartz glass is produced synthetically,

has a hydroxyl group content in the range of more than 200 wt. ppm, and

contains hydrogen in a concentration in the range of 1017 molecules/cm3 to 1019 molecules/cm3.

The examiner found that the primary reference (Moritz) satisfied each limitation of claim 1, except for being silent about a hydrogen concentration. The examiner cited a secondary reference (Ohama) describing a similar quartz glass. The quartz glass in Ohama was made from a silica powder having a hydrogen concentration overlapping the range recited in claim 1.

The examiner took the position that it would have been obvious to use Ohama’s silica starting material to prepare the quartz glass of Moritz. The examiner found that the hydrogen concentration of the finished product would be expected to be the same as that of the starting material because “[n]o evidence is given” to the contrary, and “Ohama provides no teaching or suggestion that the hydrogen is removed from the powder prior to or during formation of the inventive quartz material.”

In contrast, the applicant argued that the finished product in Ohama would not be expected to have the same hydrogen content as the starting material. In particular, the applicant argued that the sintering process in Ohama would be expected to reduce or remove molecular hydrogen from the starting material in forming Ohama’s finished product. As evidence, the applicant cited a portion of Ohama describing that the hydrogen in the starting material “react[s] with free oxygen to form OH groups, and the OH groups are fixed in the glass to suppress pore expansion from occurring.”

The PTAB agreed with the applicant. The PTAB found that “Ohama discloses that the hydrogen in Ohama’s starting material reacts with oxygen in a way that would consume Ohama’s hydrogen, such that Ohama’s final quartz glass product would not have the same hydrogen concentration as its silica powder starting material.” In a footnote, the PTAB acknowledged that the broad range of hydrogen concentration in Ohama’s starting material might allow for significant removal of hydrogen while still satisfying the claimed range for the finished product. However, since the examiner made no findings as to an expected magnitude of the decrease of hydrogen, the PTAB reversed the obviousness rejection.

Takeaway: U.S. examiners often make inferences beyond the explicit teachings of prior art references. These inferences usually are phrased in terms of what would have been expected based on the technical knowledge of a person of ordinary skill in the art. Sometimes applicants can rebut such inferences with evidence of their own. This evidence can be provided in the form of a Rule 132 Declaration, or, as in Ex parte Scheich, by reference to portions of the applied art.

Judges: Best, Kennedy, Cashion Jr.


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January 7, 2022by Beau Burton

In Ex parte Zhang (Appeal No. 2021-005022), the Patent Trial and Appeal Board (“Board”) rejected an Examiner’s finding of obviousness that was premised on an unappreciated ratio being a result-effective variable.

The independent claim on appeal read:

1. A sinterable conductive composition comprising:

a metal component having an average particle diameter of greater than about 150 nm to about 100 μm…;

a sintering agent; and

an emulsion comprising water, and

at least one particulate polymer having an average particle diameter

wherein a ratio of average metal component particle diameter to average particulate polymer particle diameter is between 1:1 and 10:1.

The Examiner rejected claim 1 over a primary reference that disclosed a metal component having an overlapping average particle diameter and a secondary reference disclosing metal particles, a sintering promoter, and an emulsion containing resin fine particles. Equating “fine particles” with nano-sized particles, the Examiner found the claimed ratio obvious (i.e., using the overlapping metal component diameter from the primary reference and the nano-sized particulate polymer diameter from the secondary reference).

In the alternative, the Examiner argued it would have been obvious to optimize the “fine particle” size to sufficiently disperse the polymer particles in the emulsion.

The Board rejected both of the Examiner’s positions. The Board first emphasized that claim 1 required a specific ratio particle size of the metal component and the polymer particle, and “not merely a size range for the polymer particle.” The primary reference did not disclose a particulate polymer so it could not possibly recognize a relationship between the metal component and the polymer particle.

As for the secondary reference, the diameter of the polymer relied on by the Examiner was for a precursor – not the final product – and nowhere did it suggest a relationship between the polymer particle size and metal particle size.

In the Board’s own words:

Missing from the record is any evidence of an interdependent relationship between the diameter sizes of the metal component and the polymer particle. In addition, nothing in the combined references suggests or recognizes that the claimed ratio relationship is a result effective variable.

We cannot accept general conclusions about what is ‘basic knowledge’ or ‘common sense’ as a replacement for documentary evidence for core factual findings in a determination of patentability.

Takeaway: Sometimes patentability resides in a relationship between properties that are seemingly obvious when considered individually. As shown in In re Zhang, when a reference relied on by the Examiner is missing the claimed property, it cannot possibly recognize a relationship involving that property. And even where a reference has the individual properties needed to arrive at the claimed relationship, the relationship will not obvious unless there is an overlap or a recognition of an interdependent relationship between the properties involved in the relationship.

Judges: C. Timm, D. Dennett, M. Cashion, Jr.