The Full Court of the Federal Court has delivered its decision in Nalco Company v Cytec Industries Inc [2026] FCAFC 72, following more than ten years of opposition, appeal, and amendment proceedings relating to Nalco’s Australian patent application directed to methods and compositions for reducing aluminosilicate scale formation in the Bayer process for alumina refining.

The appeal concerned two substantive decisions of the primary judge. The first is whether the claims then under consideration satisfied the support and sufficiency requirements of the Patents Act 1990 (Cth), with the primary judge concluding that they did not (in Cytec Industries Inc v Nalco Company [2021] FCA 970 (the 2021 Decision). The second concerned Nalco's subsequent application to further amend the claims under section 105 of the Patents Act, which the primary judge refused (in Cytec Industries Inc v Nalco Company (No 4) [2024] FCA 1318 (the 2024 Amendment Decision).

The Full Court upheld the primary judge's findings in the 2021 Decision that the claims then under consideration lacked support and sufficiency. However, it allowed Nalco's appeal from the 2024 Decision, granted the amendment application and ordered that the patent application proceed to grant on the basis of the further amended claims.

In this first article of a two-part series, we examine the first of these issues, namely the Full Court's treatment of claim construction, support and sufficiency. In the second article, we will consider the Court's important guidance on the amendment of patent applications under section 105 of the Patents Act.

The Invention

The patent application concerns methods and compositions for reducing aluminosilicate scale formation in the Bayer process, the principal process used worldwide to extract alumina from bauxite for the production of aluminum.

As explained by the Full Court, a longstanding challenge in the Bayer process is the formation of aluminosilicate scale, also referred to as desilication product (DSP), on plant equipment. Silica dissolved from the bauxite precipitates as DSP at elevated temperatures and grows as a hard glass-like film on the hot equipment. Scale formation can form obstructions and adversely affect the efficiency of the plant’s equipment and ultimately requires the equipment to be taken offline for cleaning and descaling.

The Court further noted that, prior to the priority date, two ways of managing the problem of aluminosilicate scale or DSP build-up were to reduce the amount of silica in solution going into the process through a pre-desilication process or to include additives which prevented the scale forming. One such anti-scalant was Cytec's oxysilane-based product, marketed as Max HT, which inhibits the crystallisation of dissolved silica and thereby reduces aluminosilicate scale formation.

The patent application was directed to the latter approach, namely the use of antiscalant additive. The claims were directed to methods of reducing aluminosilicate scale formation in a Bayer process by adding to a Bayer process stream a composition comprising at least one small molecule selected from a specified group of silane-based small molecules formed from the reaction of three components: an amine (i.e. hexane diamine, ethylene diamine or 1-amino-2-propanol), an amine-reactive silane containing molecule(i.e. 3-glycidoxypropyltrimethoxysilane), and an amine -reactive hydrophobic hydrocarbon (i.e. 2-ethylhexylglycidyl ether).

Procedural History

The dispute has a lengthy procedural history spanning more than a decade.

Nalco filed Australian Patent Application No. 2012220990 in February 2012. The application was accepted by the Commissioner of Patents in May 2015, following which Cytec filed an opposition to grant.

Cytec opposed the application on multiple grounds, including lack of novelty, lack of inventive step and non-compliance with section 40, alleging that the specification did not disclose the invention in a manner that was clear enough and complete enough, that the claims lacked support and clarity, and that the best method requirement had not been satisfied.

While the opposition was pending, Nalco sought to amend the accepted application in May 2016. That request was opposed by Cytec and was ultimately refused by a delegate of the Commissioner.[1]

Shortly before the opposition hearing, Nalco sought leave to amend the application again in August 2018. Cytec also opposed that application, with the result that the opposition hearing proceeded on the basis of the application as accepted.

In January 2019, a delegate of the Commissioner of Patents concluded that the opposition succeeded on the basis that the specification did not disclose the invention in a manner that was clear enough and complete enough, that the claims lacked support, and that certain claims lacked novelty and clarity.[2] However, the remaining grounds of opposition advanced by Cytec were unsuccessful. The delegate observed that there appeared to be scope for Nalco to amend the claims to overcome at least some of the successful grounds of opposition.

Shortly thereafter, Nalco filed a further request to amend the application as accepted, proposing the same amendments referred to by the delegate as overcoming the s40 grounds of opposition, together with further amendments that addressed the delegate’s finding of lack of novelty by deleting those aspects of the claims that were found to lack novelty.

However, before that amendment request could be determined, Cytec appealed the opposition decision to the Federal Court which had the consequence that Nalco’s amendment could only be made by an order of the Court in accordance with s105(1A) of the Patents Act.

Cytec appealed those aspects of the delegate's decision in the opposition on which it had been unsuccessful, seeking additional grounds on which the application could be refused. Nalco, in turn, cross-appealed the findings that had been made against it.

In November 2019, the Federal Court granted Nalco leave under s 105(1A) to amend the claims.[3]

In the 2021 Decision[4] in relation to the appeal to the opposition, the primary judge concluded that those amended claims nevertheless failed the disclosure requirement in s 40(2)(a) and the support requirement in s 40(3). Those findings turned largely on the construction adopted for the claims.

Rather than immediately appealing the 2021 Decision, Nalco sought a further opportunity to amend the claims. In December 2022, Nalco filed a further amendment application under s 105(1A), proposing a narrower set of claims intended to address the claim construction issues identified by the primary judge.

In the 2024 Amendment Decision[5], the primary judge refused that amendment application, concluding that the proposed amendments did not overcome the support and disclosure deficiencies previously identified. Orders were subsequently made dismissing the amendment application and refusing the patent application.

Nalco then sought leave to appeal both the 2021 Decision, concerning the support and disclosure findings in respect of the amended claims considered in the 2021 Decision, and the 2024 Amendment Decision refusing the further amendment application.

The 2021 Decision

The first substantive issue before the Full Court concerned the support and disclosure findings in the 2021 Decision. Those findings turned on the proper construction of claim 1.

Inparticular, claim 1 recites:

A method for the reduction of aluminosilicate containing scale in a Bayer process comprising the step of:

adding to the Bayer process stream analuminosilicate scale inhibiting amount of a composition comprising at least one small molecule

selected from the group consisting of compounds (I) through (XIII), (XV) through (XXX), (XXXII) through (XLVII), (LIII) through (LVIII) and (LX) within a product mixture formed from the reaction of a) hexane diamine, ethylene diamine or 1-amino-2-propanol; b)3-glycidoxypropyltrimethoxysilane; and c) 2-ethylhexyl glycidyl ether:…

Cytec submitted that claim 1 encompassed three categories of compositions:

(a)    embodiments where the listed small molecules are contained “within” a complex reaction product mixture - in other words the “composition” that is added to the Bayer process is the complex reaction product mixture;

(b)    embodiments where the reaction product mixture composition contains a single type of small molecule selected from the group; and

(c)     embodiments where the listed small molecules have been “selected from...within a product mixture” by isolating them from the complex product mixture within which they were formed.  

Nalco contended that claim 1 was directed to the product mixture produced by the specified reaction, which would include at least one, and in practice most or all, of the identified small molecules together with other non-identified small molecules and polymers. Although Nalco accepted that a product mixture within the claim may theoretically include a single type of small molecule, it submitted that this would be a “random happenstance” that the claim does not “require”.

The primary judge accepted Cytec's construction in part. His Honour concluded that claim 1 encompassed both (a) and (b). However, his Honour did not accept that the claim extended to (c), namely compositions in which individual small molecules had been isolated from the reaction product mixture.

The primary judge's construction of claim 1 formed the basis of the subsequent support and disclosure analysis.

The primary judge accepted that the specification disclosed reaction conditions capable of producing complex reaction mixtures containing the claimed small molecules and that the technical contribution was the general discovery that small molecule based inhibitors are effective in reducing DSP scale in Bayer refineries and that the patent application broadly describes the reaction conditions for making and maximising the yield of those small molecule based inhibitors.

However, the specification did not identify the performance of any particular small molecule in isolation, nor did it teach how to produce a reaction product mixture consisting of only one of the claimed small molecules. Although expert evidence suggested there was an infinitesimally small possibility that such a reaction mixture might arise by chance, the primary judge held that this did not amount to adequate teaching for the purpose of the support requirement .

Accordingly, insofar as claim 1 extended to compositions comprising only a single type of claimed small molecule, the claim lacked support under s 40(3). For substantially the same reasons, the primary judge concluded that the specification did not disclose the invention in a manner that was clear enough and complete enough to enable the invention to be performed across the full scope of the claim, with the result that the claim also failed the disclosure requirement of s 40(2)(a).

The Full Court Decision

On appeal, Nalco challenged the primary judge's construction of claim 1. Nalco submitted that the primary judge erred in construing the phrase "comprising at least one small molecule selected from the group consisting of … within a product mixture formed from the reaction of …" as encompassing a composition made up of a single type of identified small molecule.

Nalco submitted that, when read in light of the specification as a whole and the common general knowledge, the composition referred to in claim 1 is a product mixture formed from the reaction of the specified reactants, where that product mixture contains at least one of the identified small molecules together with other non-identified small molecules and polymers. Nalco relied upon the use of the words "comprising" and "product mixture", the definition of "comprising" in the specification, the examples, and the evidence that the reaction is random in nature and inevitably produces a complex product mixture containing identified and non-identified small molecules together with polymers.

The Full Court accepted one aspect of Nalco's construction argument, namely that the claimed product mixture inevitably includes non-identified small molecules and polymers and that the claim should not be construed as excluding those components. However, the Court considered that this distinction did not affect the outcome because the claim nevertheless encompassed compositions containing a particular identified small molecule, without the specification teaching the skilled person how to make such compositions.

The Court agreed with the primary judge at [298] that, however low the probability of obtaining such compositions from the disclosed reaction, the words of limitation chosen by the patentee "must be given work to do".

Even accepting that the proper construction of claim 1 required the composition to include at least one of the identified small molecules together with other non-identified small molecules and polymers, the claim still failed to comply with ss 40(2)(a)and 40(3), essentially for the reasons given by the primary judge. In particular, the specification did not instruct the skilled person how to make a composition comprising a specific identified small molecule, whether or not other non-identified small molecules and polymers were also present.

Accordingly, the Full Court dismissed Nalco's appeal in respect of the 2021 Decision, holding that the claims considered by the primary judge did not comply with the support and sufficiency requirements of the Patents Act.

Concluding Remarks/Key Takeaways

The Full Court's decision is yet another reminder that Australian Courts are inclined to adopt a critical approach to claim breadth and to ensuring that the scope is commensurate with the teaching provided by the specification. Other key take aways include that:

Claim breadth remains critical. A claim must be supported and enabled across its full scope, including embodiments that may be unlikely to occur in practice.

‍Every claim limitation matters. The Court reaffirmed that the words chosen by the patentee "must be given work to do" and cannot later be treated as inconsequential.

‍Claim construction is not determinative. Even where a patentee succeeds on aspects of claim construction, the claims may still fail if the specification does not support or enable the full scope claimed.

‍Specifications should match the monopoly sought. Applicants should ensure that the specification teaches the skilled person how to make and use the full range of claimed embodiments.

‍Include meaningful fall-back positions. Where broad claims may be vulnerable, narrower claims directed to fully enabled embodiments may prove invaluable.

In Part 2 of this series, we examine the second substantive issue on appeal, namely whether the primary judge erred in refusing Nalco's subsequent amendment application under s 105 of the Patents Act. Although the Full Court upheld the primary judge's findings on support and sufficiency, it reached a different conclusion in relation to the proposed amendments and ultimately ordered that the patent application proceed to grant on the basis of the further amended claims.

[1]Cytec Industries Inc. v Nalco Company [2018] APO 4

[2]Cytec Industries Inc v Nalco Company [2019] APO 2

[3]Cytec Industries v Nalco Company [2019] FCA 1800

[4]Cytec Industries Inc v Nalco Company [2021] FCA 970

[5]Cytec Industries Inc v Nalco Company (No 4) [2024] FCA 1318

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