Consider the Bar Raised for Sufficiency and Support: Nalco Patent Application Claiming Inhibitors of Silica Deposits Invalid

Date: 19 August 2021
Court:  Federal Court of Australia
Judge: Burley J

Background

The ‘Bayer process’ has been used for over 130 years to extract alumina from bauxite to make aluminium. In this process, crushed bauxite is added to a caustic liquor at high temperature and circulated around tanks in a refinery. The alumina dissolves in the liquor, separating it from other minerals in the bauxite, which remain in a slurry. Those minerals include silica, which is deposited on tank surfaces as scale. Eventually, this scale must be removed from the tanks, which is costly.

Nalco Company (Nalco)’s Patent Application 2012220990 (Application) claimed methods for reducing such scale by adding to a Bayer process a mixture comprising at least one small molecule selected from a group of molecules, that mixture resulting from a reaction between specified compounds. Nalco’s competitor Cytec Industries Inc. (Cytec) opposed the grant of the Application.

At first instance, the Delegate found all claims of the Application invalid on several grounds. Nalco appealed to the Federal Court and amended the claims of the Application to overcome the Delegate’s objections.

Key Issues

During the appeal, the key issues raised were enablement, support and best method. An issue also arose as to the application of the grace period to ‘whole of contents’ prior art.

Outcome

Enablement and Support

Burley J considered that the amended claims included within their scope a reaction mixture containing only one of the small molecules recited in the claims. The expert witnesses agreed that the reaction would produce an extremely large variety of small molecules, including all of those in the group of molecules specified in the claims. It was a virtual impossibility that the reaction would result in only one member of the group (as one expert said, this would be “like trying to win the lottery in every country in the world with the same six numbers on the same weekend”). In consequence, the lower limit of the claims was not enabled and all of the claims were invalid.

In relation to the support requirement post-Raising the Bar, Burley J referred to his own statement of the law in Merck Sharp & Dohme v Wyeth (No 3),¹ including that the technical contribution to the art of the specification must justify the breadth of the monopoly claimed. He concluded that the Application did not disclose how to make a reaction mixture containing only one of the small molecules from the group of molecules recited in the claims. Therefore, for essentially the same reason as the claims were not enabled, all claims of the Application for lacked support.

Best Method

The experts agreed that the examples in the Application disclosed methods for making reaction mixtures in the laboratory but did not provide enough detail to enable the examples to be replicated at scale. Cytec submitted that the omitted details were part of the best method of practising the invention known to Nalco when it filed the Application.

Burley J was not persuaded, considering that the claimed invention was an industrial process and that the laboratory synthesis methods in question could only provide a rough starting point for developing the process on an industrial scale; they were not a proxy for it. The missing details of Nalco’s laboratory method were not therefore part of the best method. Because Nalco had not in fact made reaction mixtures on an industrial scale, somewhat curiously, there was no best method for it to withhold in this respect.

Grace Period

Cytec contended that the claimed invention was anticipated by a related Nalco patent application as ‘whole of contents’ prior art i.e. prior art published after the priority date of the Application, but entitled to an earlier priority date. Nalco relied on the twelve month grace period for information made publicly available by the applicant; Cytec argued that the grace period did not apply to ‘whole of contents’ documents. Burley J held that the grace period applied in respect of the relevant prior art.

Implications

Where a claim includes a limitation of “at least” a particular parameter, it is essential that the invention works and is enabled when the parameter is set at that minimum.

Further, where a claimed invention can only be implemented on a larger scale (e.g., industrial or commercial scale) than is disclosed in a patent application, a failure to disclose the best method of practising the invention at a smaller scale (e.g., laboratory scale) may not be fatal to the validity of the application, unless the evidence indicates that the parameters used at the smaller scale can be scaled up for use at the larger scale.

Finally, it has been clarified that the grace period will apply to whole of contents novelty references where the other requirements are met.

1. [2020] FCA 1477