obviousness Archives - Page 4 of 9

In Ex parte Price (Appeal 2021-003888), the Patent Trial and Appeal Board (“Board”) reversed the Examiner’s obviousness rejection because of Appellant’s successful showing of unexpected results.

Claim 1 was illustrative and read:

A ballistic material, comprising:

a first woven para-aramid ballistic fabric having a fiber denier in a range of 50 d to 5000 d; and

a hydroentangled nonwoven fiber component consisting essentially of ballistic grade para aramid fibers having a denier in a range of about 0.5 d to about 2.5 d and a density of about 10 gsm to about 200 gsm; wherein

the hydroentangled nonwoven component is needlepunched with the woven ballistic fabric to form a consolidated material.

The Examiner rejected claim 1 as obvious over Price in view of Van der Loo. Price taught a similar consolidated material but was silent on its non-woven component being “hydroentangled.” Instead, Price’s nonwoven was manufactured, for example, by dry laid carding and mechanical needling. The Examiner thus turned to Van der Loo and found that Van der Loo provided suggestion of using hydroentangling instead of needling to form a nonwoven.

The Board did not find that the Examiner’s combination of Price and Van der Loo was unreasonable. However, the Board found that the Examiner failed to give proper weight to Appellant’s evidence of unexpected results presented by Declarant Brahms.

The Board noted that Appellant first provided evidence regarding the expectation of the ordinary artisan. In particular, according to Appellant, “[t]he expectation in the art is that an identical stack of woven para-aramid layers reinforced with the same weight of nonwoven para-aramid fibers of the same denier would yield the same ballistic performance.” Appellant supported this statement with evidence showing linearity of the correlation between weight and ballistic performance measured as V-50.

Appellant then provided declaratory evidence that their results were significantly different from those of the closest prior art. In particular, after comparing the V-50 performance of shoot packs formed of ballistic materials made with identical materials and by identical processes except for the use of a non-woven that was hydroentangled versus needled, Brahms declared the observed difference was not merely random as verified by statistical analysis.

Finally, Brahms declared that the result was unexpected. In particular, according to Brahms, “[w]hen we first substituted spunlace material, we had hoped for some processing advantages and some reduction in weight for the final ballistic product. We did not expect an improvement in ballistic properties.” Brahms further declared that “[s]pecifically, an amount of fiber material, incorporated as spunlace, produced unexpected advantages in terms of the ballistic performance as compared to the same amount of fiber material incorporated from a needled batting. We now believe that the improvement in ballistic performance is due to the availability of the fibers of the spunlace material.”

The Board dismissed the Examiner’s determination that Appellant’s results were expected, because the Examiner improperly discounted Brahms’s specific statements that the difference was unexpected in that it was surprising that lower weight products would achieve V-50 ballistic performance improvements above the normal linear correlation seen in other known products.

Takeaway: Any differences between a claimed invention and prior art may be expected to result in some differences in properties. What matters is whether the differences in properties are of a magnitude that really would have been unexpected. Ex parte Price illustrates a scenario where applicant can prove unexpected results by showing results that are “greater than” what is normally expected.

Judges: A. L. Hanlon, C. Q. Timm, and N. W. Wilson

In attempting to overcome obviousness rejections, our initial focus often centers on the differences between the cited references and the claimed invention. We do this in the hope of finding reasons that, even when the references are combined, the claimed invention would not be taught (no prima facie case). When such reasons are not present, we then generally look for a lack of motivation to combine the references which, unfortunately, has lately become more and more difficult to establish. However, in August the Federal Circuit issued a decision in Eli Lilly & Co. v. Teva Pharm. Int’l GmbH, 2020-1876 (Fed. Cir. Aug. 16, 2021) reminding us that, even where there is motivation to combine references, and even when all the claim limitations are provided by the combination, there is a third, separate requirement that must be met in order to establish a prima facie case of obviousness – a reasonable expectation of success in accomplishing what is required by the claims must also be present.

The Eli Lilly decision was one of three decisions issued on the same day in related inter partes review proceedings between Eli Lilly and Teva concerning patents related to monoclonal antibodies useful for the treatment of headaches. Importantly, in Eli Lilly the court found the claims’ preamble statements of “intentional purpose” (i.e., treating headaches) to be limiting. Then, citing Novartis Pharm. Corp. v. W.-Ward Pharm. Int’l Ltd., 923 F.3d 1051 (Fed. Cir. 2019) and summarizing the holding in that case as finding that “it was not enough for the [defendant] to have shown that a skilled artisan would have pursued the claimed method as a treatment option, but the [defendant] also had to show that the skilled artisan would have reasonably expected to achieve success in the treatment,” the Federal Circuit affirmed the PTAB’s finding that Lilly had failed to establish a reasonable expectation of success in pursuing the claimed method due to the uncertain and unpredictable nature of the underlying technology, even though the applied references taught all the limitations of the contested claims, and even though there was motivation to combine the references.

The Eli Lilly case is thus a good reminder for patent practitioners that, even in the face of what appears to be a very good prima facie case, there may be a pathway to patentability through the “no reasonable expectation of success” route, especially in unpredictable/newly developing arts.

Judges: Lourie, Bryson, O’Malley

In Ex parte Talamoni (Appeal No. 2020-006553), the Patent Trial and Appeal Board (“Board”) rejected an Examiner’s claim construction overriding the phrase “derived from the reaction product of” with “comprising.”

The independent claim on appeal read:

A composition comprising an acrylic adhesive derived from the reaction product of

(a) an acrylic ester of monohydric alcohol having an alkyl group of the 5 to 10 carbon atoms; and

(b) a nonpolar acrylic monomer having a solubility of less than 9.2 as measured by the Fedors method using a homopolymer of the nonpolar acrylic monomer,

wherein the reaction product has a side chain crystallinity.

The Examiner rejected the claim as anticipated by or, in the alternative, obvious in view of a reference that disclosed a terpolymer produced from monomers (a) and (b) and 0.5–5 wt% of a monomer (c) (a monoolefinically unsaturated ketone). The Examiner argued the “side chain crystallinity” although not disclosed would be present in view of In re Spada (i.e., “[w]hen the PTO shows a sound basis for believing that the products of the applicant and the prior art are the same, the applicant has the burden of showing that they are not”). The Board disagreed.

At the outset, the Board found that the phrase “derived from the reaction product of” monomers (a) and (b) would be understood by those of skill in the art to exclude the terpolymer of the prior art derived from monomers (a), (b), and (c). The Board did agree that the use of “comprising” in the preamble opened the claim up to additional unrecited ingredients such as tackifiers but it did not override or expand the requirement for a reaction product obtained from the two monomers (a) and (b). Accordingly, the Board reversed the anticipation rejection.

As for obviousness, the Board found that the prior art taught away from omitting monomer (c) since it taught the monomer (c) provided the terpolymer with stability and stated, “if the amount of monomer (c) is less than 0.5 mass %, an insufficient effect is produced by the addition.” With no reason for why a person of ordinary skill in the art would have been motivated to omit monomer (c) from the prior art, the Board reversed the obviousness rejection.

Finally, the Board emphasized that the Examiner was not entitled to rely on the presumption from Spada because Appellant’s claim did not cover a reaction mixture containing monomer (c) and the breadth of monomer (c) in terms of the amount and potential species was too broad to conclude that the prior art’s terpolymer was substantially identical to the claimed copolymer of monomers (a) and (b).

Takeaway: In re Talamoni is notable for two reasons. First, the Board found the phrase “derived from the reaction product of … (a) … and (b)” to be closed. While savvy US applicants are accustomed to “comprising” and “consisting of,” phrases like this tend to be more common in applications originating outside the US. Accordingly, it is a good practice to replace uncommon transitional phrases with the corresponding US equivalent (e.g., comprising, consisting essentially of, or consisting of) to limit these types of disputes. And second, the Board correctly found that use of the transitional phrase “comprising” in the preamble did not render the following transitional phrase obsolete. Unfortunately, this type of interpretation before an Examiner is not uncommon, but it is promising to see the Board consistently reaching the correct conclusion. See, e.g., https://www.elementiplaw.com/comprising-is-not-a-weasel-word/ (PTAB rejecting an Examiner’s attempt to construe “comprising … a single odorant chamber” to allow for a plurality of chambers).

Judges: G. Best, N. Wilson, M. Cashion, Jr.

In Ex parte Easson (Appeal 2020-001129), the Patent Trial and Appeal Board (“Board”) reversed the Examiner’s obviousness rejection because the Examiner failed to show the prior art composition with the required components necessarily had the claimed properties.

Claim 21 was illustrative and read:

A directly compressible tableting composition, comprising 50-85% by weight of anhydrous calcium hydrogenphosphate, 10-40% by weight of mannitol and 5-20% by weight of sorbitol, wherein said composition has a flow angle in the range of 29 to 33.4° and a bulk density in the range of 0.56 to 0.77 g/ml with a tapped density in the range of 0.73 to 0.92 g/ml.

The Examiner rejected claim 21 as obvious over Yokoi in view of Ranchhordas and Reiff. In particular, the Examiner found that Yokoi taught a powdered composition for tablets that had the same components in overlapping amounts. The Examiner contended that the claimed flow angle range was an inherent property of the claimed composition and thus the composition described in Yokoi must have the same flow angle. The Examiner found that Ranchhordas and Reiff described bulk densities of anhydrous calcium hydrogen phosphate and sorbitol, respectively, both of which overlapped with the claimed bulk density range. The Examiner thus concluded the mixture of the two had the claimed bulk density. Regarding the tapped density range, although the Examiner admitted that the references did not teach the property, he reasoned that “[because] all other properties are overlapping[,] the tapped density would be expected to overlap as well.”

Appellant argued that the Examiner misapplied the law of inherency and that the recited properties were additional limiting requirements of the claimed invention that would not be necessarily possessed by any composition with the recited components. The Board agreed.

In particular, regarding the bulk density, the Board noted that the claimed composition was a mixture of three components and that there was no evidence in the record disclosing the bulk density of mannitol, which was a component other than anhydrous calcium hydrogenphosphate and sorbitol. Also, the Board pointed out that claim 21 encompassed a composition containing as little as 50 wt% of anhydrous calcium hydrogenphosphate, 10 wt% of mannitol, and 5 wt% of sorbitol; that is, the claimed composition could contain as much as 35 wt% of unspecified ingredients with unknown bulk densities. The Board thus concluded that it was not necessarily true that any composition encompassed by claim 21 would have the claimed bulk density.

The Board further found evidence of record that contradicted the Examiner’s inherency conclusion. Specifically, the Board found Appellant’s specification described five compositions containing proportions of anhydrous calcium hydrogenphosphate, mannitol, and sorbitol within the recited ranges; however, two of these compositions had bulk densities and tapped densities that were too high to fall within the specified ranges.

Takeaway: When faced with a composition claim containing property limitations, examiners often assert the properties are inherent if they find a prior art composition satisfying the claimed composition limitations. However, that a property may occur or be present in the prior art is not sufficient to establish inherency. To rely on a theory of inherency, an examiner “must provide a basis in fact and/or technical rationale to reasonably support the determination that the allegedly inherent characteristic necessarily flows from the teachings of the applied prior art.” Ex parte Levy, 17 U.S.P.Q. 2d 1461, 1464 (B.P.A.I. 1990). As illustrated by Easson, an inherency argument lacking such reasoning does not establish a prima facie case of anticipation and/or obviousness, particularly when there is counter evidence showing the properties are additional distinguishing requirements that are not merely results of the composition limitations.

Judges: D. E. Adams, E. B. Grimes, and J. N. Fredman

Ex parte Kuhlmann, is a recent decision of the Patent Trial and Appeal Board (PTAB) addressing prima facie obviousness of a polymer composition.

The substance of the decision in Ex parte Kuhlmann is not particularly remarkable – the examiner was affirmed by the PTAB. However, applicant argued that the allowance of a corresponding application in Europe was relevant to the issue of obviousness in the US, and the argument was not well-received.

In the Appeal Brief, applicant argued:

For reference, the Applicants respectfully submit that the EPO equivalent application EP 3255103 was granted and found to be novel and non-obvious over the US Dangayach et al. (US 5,284,938, herein Dangayach A) reference.

In the Examiner’s Answer, the examiner stated:

In response to Appellant’s statement, p. 9 of the Brief, that EP 3255103 was found novel and non-obvious over the Dangayach A is not persuasive, because that determination was not under US patent laws and rules.

In the Reply Brief, applicant further argued:

If relevant to the Appeal Board, the Appellants submit that the claims as submitted in the Appeal are identical or substantially identical to the claims granted (without issuance of an Action) in European patent EP3255103B1 and validated in 14 countries, which claims were granted over Dangayach et al. (US 5,284,938, herein Dangayach A), the main reference cited by the Examiner herein, for reasons which will further be obvious below.

And finally, in the Decision, the PTAB stated:

We find no merit in Appellant’s argument that the same or substantially the same claims in EP 3255103 B1 were found novel and nonobvious over Dangayach and thereby granted by the European Patent Office (EPO)… We are not bound by an earlier decision of the EPO. In re Gyurik, 596 F.2d 1012, 1016 (CCPA 1979) (“Each case is determined on its own merits; allowed claims in other applications or patents are not considered in reviewing specific rejections of specific claims.”); In re Giolito, 530 F.2d 397, 400 (CCPA 1976) (“We reject appellants’ argument that the instant claims are allowable because similar claims have been allowed in a patent. It is immaterial whether similar claims have been allowed to others.”).

Takeaway: Prosecuting corresponding patent applications in different countries can be expensive and time consuming. Common sense would suggest that something that is patentable in one jurisdiction should generally be patentable in all jurisdictions. Of course, the patent laws differ from jurisdiction-to-jurisdiction. The US can be particularly idiosyncratic, as US examiners often rely on different references and/or rationales than examiners in other jurisdictions. As is evident from Ex parte Kuhlmann, directly asserting that US claims should be allowed based on an allowance in another jurisdiction can be counterproductive. A more productive approach would be to rely on the reasons for allowance in another jurisdiction to the extent they are applicable under US law. The fact of allowance in another jurisdiction might be of interest to some US examiners – but this might be better conveyed informally in an interview.

Judges: Timm, Praiss, Gupta

Ex parte Lindenblatt, is a recent decision of the Patent Trial and Appeal Board (PTAB) addressing evidence of unexpected results.

In Ex parte Lindenblatt, the claim at issue was directed to a pharmaceutical (thyroid hormone) formulation. The relevant claim recited:

1. A solid pharmaceutical preparation comprising

levothyroxine sodium,

2-10% by weight based on the preparation of gelatine,

0.2 to 3% by weight based on the preparation of citric acid, and

a filler that is 50 to 80% by weight, based on the preparation, of mannitol, sucrose or lactose, and 10 to 30% by weight, based on the preparation, of maize starch.

In rejecting the claim, the examiner relied on a primary reference that disclosed all of the features except for the gelatin. For this deficiency, the examiner relied on a secondary reference disclosing levothyroxine sodium tablets including gelatin and fillers and describing that, when gelatin is used as a binder, the tablets have surprising stability.

Applicant argued that the tablet of the primary reference was intended to dissolve rapidly in a patient’s mouth and, thus a skilled artisan would not have been led by the secondary reference’s promises of stability through the use of gelatin.

The PTAB was not persuaded, finding that the examiner made a prima facie case of obviousness. The PTAB noted particularly that “while [the primary reference] is concerned with a composition that can easily dissolve in the mouth, such does not indicate that [the primary reference] is not interested in a product that has a stable shelf life until inserted into the mouth of a patient.”

The PTAB was persuaded, however, by applicant’s evidence of unexpected results.

First, applicant provided evidence (a journal article) showing that it was known that citric acid is a pH modifier that reduces the stability of levothyroxine sodium in tablets relative to tablets including a basic pH modifier or no pH modifier (at 10% – much higher than the claimed range and the primary reference). Then, applicant supplemented with experimental evidence, which showed the following results for stability when varying citric acid and gelatin amounts in levothyroxine sodium tablets:

Citric Acid	Gelatin	Stability
1.5%	–	★
–	–	★★
–	5%	★★★
1.5%	5%	★★★★

Looking at the evidence, the PTAB found that the stability results for the combination of gelatin and citric acid would have been unexpected, because citric acid alone was reported in the literature and shown in applicant’s experimental results to negatively affect the stabilization of levothyroxine sodium in a tablet. That is, the PTAB concluded that a skilled artisan would not have expected the combination of citric acid and gelatin to provide better stabilization of levothyroxine sodium in a tablet composition than the stabilization provided by gelatin alone.

Takeaway: In this case, the examiner provided a credible reason for expecting that addition of gelatin to the citric acid-containing tablets of the primary reference would increase stability – the secondary reference explicitly stated that stability would be increased. Applicant was able to find literature evidence suggesting that a large amount of citric acid is expected to destabilize. Applicant supplemented this with post-filing results showing that small amounts of citric acid destabilize. Together, this evidence persuaded the PTAB that the improved performance of the citric acid/gelatin combination shown by applicant was unexpected.

Applicant provided a good amount of evidence and a compelling narrative regarding unexpectedness. The PTAB’s explanation, however, gives little weight to the fact that the primary reference tablets already included citric acid. Further, the post-filing evidence regarding the effect of small amounts of citric acid would not have informed a skilled artisan of what would have been expected or unexpected at the time of the application. This case illustrates that sometimes a persuasive story can be useful in overcoming weaknesses in evidence of unexpected results.

Judges: Adams, Jenks, Townsend

Equivalence is a common tool used by Examiners to demonstrate the obviousness of a claimed component that is known to be interchangeable with a component in the prior art. However, Ex parte Breder illustrates that the interchangeability alone is insufficient for obviousness – the context of the equivalence is key. Appeal No. 2021-002289 (PTAB Oct. 5, 2021) (non-precedential).

In Breder, the claims were directed to a method of antagonizing 5-HT7 and 5-HT1B receptor activity in a patient suffering from ADHD by administering viloxazine. The primary reference relied on by the Examiner taught a method of treating ADHD with a norepinephrine reuptake inhibitor reboxetine. The primary reference emphasized the high selectivity of reboxetine for norepinephrine processing and its efficacy for treating ADHD, but said nothing whatsoever about viloxazine.

Attempting to present a prima facie case of obviousness for the treatment of ADHD with viloxazine, the Examiner found a secondary reference that disclosed reboxetine and viloxazine as norepinephrine reuptake inhibitors and alleged that a skilled artisan “would have been motivated to substitute the norepinephrine reuptake inhibitor, viloxazine, … with the norepinephrine reuptake inhibitor, reboxetine, in the method of treating ADHD.” Despite this apparent equivalence, the Board did not agree.

From the Board’s perspective, any functional equivalence between viloxazine and reboxetine as norepinephrine reuptake inhibitors was outweighed by the secondary reference had nothing to do with ADHD. In fact, the secondary reference was directed to a topical composition for the transdermal delivery of active agents for ailments such as muscle pain and muscle cramps, which could optionally include norepinephrine reuptake inhibitors. According to the Board, the “sole nexus between the teaching of [the prior art]” is “that reboxetine and viloxazine are norepinephrine reuptake inhibitors,” and this was not enough.

Simply put, the Board did not agree that an optional ingredient in a topical composition for treating muscle pain provided sufficient motivation for a skilled artisan to replace the reboxetine with viloxazine in a complexly different method for treating ADHD, with a reasonable expectation of success. The primary reference’s emphasis on the high selectivity and efficacy of reboxetine bolstered this conclusion.

Takeaway: Context is key. Functional equivalence can be essential for a prima facie case when the primary reference lacks a claimed component but includes a component known to be interchangeable with it. But as shown by Breder, this functional equivalence will not carry the day when the references being combined have nothing in common. Therefore, it is important to thoroughly assess the purpose and end use of each of the references being combined when an Examiner relies on a theory of functional equivalence for the obviousness of a claimed component.

Judges: R. Lebovitz, J. New, D. Cotta

“A picture is worth a thousand words.” This is also true, and sometimes may be even more so, in patent applications. However, one should be careful about what a figure in a patent application does and does not say. A recent decision of the Patent Trial and Appeal Board (“Board”) in Ex parte Hogard (Appeal 2020-006394) illustrates this point.

Appellant in Hogard claimed a method of controlling a fluid level in a venous drip chamber of a dialysis system having a blood pump and an air pump. The claimed method required operation of the blood pump in first and second modes that resulted in the fluid (i.e., either blood or saline) moving both forwards and backwards through the tubing set.

The Examiner rejected the claimed method as obvious over Heyes in view of Folden. The Examiner admitted that Heyes did not disclose the claimed priming sequence. However, the Examiner cited Folden, which taught bi-directional flow, as making up for the deficiency of Heyes.

Relying on Heyes’ Figure 7 (viewable here), Appellant argued that Heyes’ fluid path was meant to be unidirectional only and the Examiner’s proposed modification would have rendered Heyes’ device inoperable. In particular, noting that Figure 7 illustrated aperture 30 of bubble trap 34 being above level sensor 44, Appellant argued that if saline flowed in the reverse direction through the bubble trap, due to the position of inlet lip 36 (which was the entry point to aperture 30), the saline level would have to be higher than level sensor 44. Appellant argued that having no control of the fluid level within the chamber would have caused the hydrophilic membrane covering the vent in bubble trap 34 to become wetted and non-useful. Therefore, Appellant argued that the Examiner’s proposed modification of Heyes by Folden to have priming fluid flow in the reverse direction during priming would have caused Heyes’ bubble trap 34 inoperable due to a wetted hydrophilic membrane.

The Examiner raised two counter arguments in his answer. First, the Examiner argued Appellant’s arguments regarding the location of aperture 30 were moot because the drawings of Heyes were not to scale. Second, the Examiner argued even if aperture 30 was above level sensor 44, it would have been obvious to configure Heyes’ bubble trap 34 so that the level sensor prevented saline from contacting the hydrophilic membrane.

Appellant agreed Heyes did not indicate that its figures were drawn to scale. However, citing Vas-Cath Inc. v. Mahurkar, 935 F.2d 1555, 1565 (Fed. Cir 1991), Appellant argued that the drawings could be used to establish “relative sizes and relationship between the various components which are clearly depicted in those drawings.” Specifically, Appellant argued that the relative positions of aperture 30, level sensor 44, and the hydrophilic membrane of bubble trap 34 depicted in Heyes’ Figure 7 made it clear that Heyes’ bubble trap 34 was designed only for unidirectional flow. In response to the Examiner’s second counter argument, Appellant argued modification of Heyes’ bubble trap 34 to operate bi-directionally amounted to a significant change in the function of Heyes’ device.

The Board was persuaded by Appellant’s arguments. The Board agreed with Appellant’s interpretation of Heyes’ Figure 7 and pointed out that “[p]atent drawings may not be disregarded for items that they clearly show.” The Board also sided with Appellant’s position regarding the change in function and emphasized that “[i]f the proposed modification or combination of the prior art would change the principle of operation of the prior art invention being modified, then the teachings of the references are not sufficient to render the claims prima facie obvious.” The Board further noted the well-settled law that “which is within the capabilities of one skilled in the art is not synonymous with obviousness” and that “[t]he mere fact that the prior art may be modified in the manner suggested by the Examiner does not make the modification obvious unless the prior art suggested the desirability of the modification.”

Because the Board concluded that there was no suggestion in the applied art to modify Heyes’ system for unidirectional flow by Folden’s method of priming a dialysis system using bi-directional flow, the Board reversed the Examiner’s obviousness rejection.

Takeaway: If a reference does not disclose that the drawings therein are to scale and is silent as to dimensions, arguments based on measurements of features in the drawings are of little value. However, an examiner can rely on features of drawings that are not explicitly described in a reference, if the meaning or intent of such features would be apparent to one of ordinary skill in the art viewing the reference. Ex parte Hogard illustrates a situation where an applicant was similarly able to rely on the manner in which a skilled artisan would have understood the drawings to rebut a rejection.

Judges: B. A. Franklin, J. B. Roberstson, and C. C. Kennedy

Process (or method) claims recite one or more actions or steps to be performed. For example: a process for producing NaCl, comprising steps A, B and C. In contrast, product-by-process claims recite a product that is produced by a certain process. For example: NaCl, produced by a process comprising steps A, B and C.

In determining whether a process claim is obvious, a U.S. examiner compares the claimed process to the prior art, and asks whether the prior art suggests all the limitations (i.e., all actions or steps) recited in the process claim. In the example above, the examiner would assess the prior art for a suggestion of steps A, B and C.

The inquiry is somewhat different for a product-by-process claim. For infringement purposes, a product defined by a product-by-process claim is limited by the process. However, the patentability of the product does not depend on the process but on the product itself. In the example above (NaCl, produced by a process comprising steps A, B and C), the examiner would assess the prior art for a suggestion of the product (NaCl) not for a suggestion of the process (steps A, B and C). If the examiner could provide a rationale tending to show that the product appeared to be the same as or similar to that of the prior art, although produced by a different process, the burden would shift to the applicant to provide evidence establishing a nonobvious difference between the claimed product and the prior art product.

This important difference between process claims and product-by-process claims is illustrated in the recent Patent Trial and Appeal Board (“Board”) case of Ex parte Liu (Appeal No. 2020-006403).

Independent claim 1 recited:

A pot furnace low-temperature calcination method comprising:

providing a pot;

providing a flame path proximate to the pot such that heat from the flame path heats the pot;

controlling a flame path temperature and discharge rate of the pot furnace such that petroleum coke is calcined in the pot at a temperature range from 1150°C to 1220°C, the discharge rate of the pot being controlled to be 110 – 120 kg/hr; and

reducing an amount of desulfurization of the petroleum coke during calcination so that true density of the calcined coke is between 2.05 and 2.07 g/cm³;

wherein the flame path temperature is controlled to be less than 1250°C.

The examiner rejected claim 1 as obvious. In response, the applicant argued that the applied prior art did not suggest the process limitation of a discharge rate of 110 to 120 kg/hr. On appeal, the examiner seemed to apply a product-by-process interpretation to the claimed discharge rate: “It is not necessary for the reference to make or recognize the same mental correlation or relationship as appellant, nor to heat for the same reasons, as long as the product made is the same or essentially the same” (emphasis added).

The Board agreed with the applicant. The Board noted that “the claim is a method claim and not a product-by-process claim. Thus, it is the method step recitations that cannot be skipped in making an obviousness determination.” Accordingly, the Board reversed the obviousness rejection.

Takeaway: It is important to keep in mind the difference between process claims and product-by-process claims. If an examiner refuses to give patentable weight to a process limitation because he considers it to be a product-by-process limitation, this can form the basis of a successful appeal.

Judges: Franklin, Gupta, Inglese

Ex parte Slark, is a recent decision of the Patent Trial and Appeal Board (PTAB) addressing whether the changes to a prior art composition that would result from an examiner’s proposed modification were sufficiently dramatic to negate obviousness.

In Ex parte Slark, the claim at issue was directed to a hot melt adhesive composition. The relevant claim recited:

A non-reactive hot melt adhesive composition comprising two thermoplastic polyurethane copolymers (A) and (B), wherein

the thermoplastic polyurethane copolymer (A) comprises a reaction product of at least one polyester polyol, and at least one polyisocyanate, and has a number average molecular weight (M_n) of at least 25,000 g/mol;

the thermoplastic polyurethane copolymer (B) comprises a reaction product of at least one polyester polyol, and at least one polyisocyanate, and has a number average molecular weight (M_n) of less than 25,000 g/mol; and

wherein the hot melt adhesive composition has a melt viscosity of 1,000 to 100,000 mPas at 160 °C and

wherein both thermoplastic polyurethane copolymers (A) and (B) are essentially free of NCO groups.

The examiner cited a primary reference that disclosed a solvent-free hot melt adhesive composition including two thermoplastic polyurethane copolymers, each copolymer being a reaction product of at least one polyester polyol and at least one polyisocyanate. The examiner acknowledged that the primary reference failed to disclose that the hot melt adhesive was non-reactive or that the polyurethane copolymers were essentially free of NCO groups. The examiner noted particularly that the preferred ratio of NCO groups to OH groups in the copolymers of the primary reference (>1) would not result in a “non-reactive” composition in which the copolymers were “essentially free of NCO groups.”

To address this deficiency, the examiner turned to a secondary reference. The secondary reference disclosed a solvent-free hot melt adhesive composition including a polyurethane obtained from a polyester polyol and an isocyanate, in which the ratio of NCO groups to OH groups in the polyurethane (~1) resulted in a “non-reactive” composition in which the polyurethane was “essentially free of NCO groups.” The examiner asserted that it would have been obvious to modify the polyurethanes of the primary reference to have the NCO:OH ratio of the polyurethane of the secondary reference, because the secondary reference disclosed that the ratio was suitable for reacting a polyester polyol with a polyisocyanate such that the resulting hot melt adhesive would be essentially free of NCO groups and nonreactive.

Applicant argued over the rejection by relying on two non-obviousness arguments that are explicitly identified in the MPEP: (1) modifying the composition of the primary reference as proposed by the examiner would render the composition “unsatisfactory for its intended purpose” (MPEP 2143.01.V); and (2) modifying the composition of the primary reference as proposed by the examiner would “change the principle of operation” of the composition (MPEP 2143.01.VI).

With respect to (1), applicant argued that the primary reference was directed to a reactive thermoset hot melt adhesive composition – not a non-reactive thermoplastic composition as required by the claims. Applicant noted that the purpose of the primary reference was to provide a moisture reactive polyurethane hot melt adhesive having a particular cured strength and excellent adhesion to metals. Applicant argued that the examiner’s proposed modification would eliminate essentially all of the isocyanate moieties in the prepolymers, rendering them non-reactive and unsatisfactory for the intended purpose of the primary reference. With respect to (2), applicant similarly argued that, because the examiner’s proposed modification involved eliminating the isocyanate groups from the prepolymers, the principle of operation of the composition of the primary reference would be different – the composition would no longer be a reactive, moisture-curable thermosetting polyurethane adhesive composition.

The PTAB agreed with applicant. The PTAB indicated that the “intended purpose” and “principle of operation” of the adhesive composition of the primary reference were intertwined. The examiner attempted to broadly characterize the composition of the primary reference as involving adhesion – an intended purpose and principle of operation that would be preserved even if the examiner’s proposed modification was made. However, the PTAB indicated that the examiner should have considered the contribution of the primary reference to the art when identifying the intended purpose and principle of operation. The PTAB noted that the primary reference expressly stated that mixtures of isocyanate-terminated polyurethanes provide good adhesion to metal substrates by achieving an initial bond strength upon cooling on a substrate and eventually achieving an ultimate bond strength when cured with ambient moisture. The PTAB agreed with applicant that the examiner’s proposed modification would render the composition of the primary reference unsatisfactory for its intended purpose and would change the principle of operation.

Takeaway: When facing obviousness rejections of chemical compositions, it can be difficult to persuade an examiner that he or she has failed to make a prima facie case. Absent a plain oversight by the examiner regarding the scope of the claims or prior art, it is often necessary to significantly narrow the scope of the claims and/or rely on experimental evidence of unexpected results. However, there are legal arguments that can be effective in overcoming obviousness arguments without amendments or experimental results – and the MPEP remains a great source for identifying compelling reasoning for arguing over obviousness rejections.

Judges: Hanlon, Housel, Inglese

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