Sometimes it is necessary to claim chemical compositions that consist of more than one material. Such compositions can be thought of as mixtures and have practicalutility across the spectrum of the chemical arts. For example, alloys are typicallymixtures of metals that can possess desirable properties very different from what any given component might have. Other examples include pharmaceutical formulations,which typically contain a mixture of one or more drug substance together wit hone or more pharmaceutical excipients, chosen in such a way as to maximize the desired pharmaceutical properties of the drug substances. Chemical mixtures are typically claimed by representing different components of the mixtures together with a percentage range for that component in the mixture. For example, consider two composition claims for a titanium-based alloy:

We claim:

  1. A titanium metal base alloy consisting essentially by weight of about 0.6% to 0.9%nickel, 0.2% to 0.4% molybdenum, up to 0.2% maximum iron, balance titanium, saidalloy being characterized by good corrosion resistance in hot brine environments.

  2. A titanium base alloy as set forth in claim 1 having up to 0.1% iron, balance titanium.

As you can see, the claimed alloy can contain up to four different metals, where in at least three metals must be present (nickel, molybdenum, and titanium), and one metal can be present in up to a limited amount (iron, up to 0.2%).29 The second claim is dependent from claim 2, having a narrower scope since the iron is still an optional ingredient but it is now limited to a narrower range. Accordingly, it is possible to infringe claim 1 without infringing claim 2, but it is not possible to infringe claim2 without infringing claim 1. Just as for the compounds discussed in the previous section, a claim to a mixture must be novel to be patentable. In order to understand what makes a range novel or not novel, we’ll examine the case Titanium Metals Corp.V. Banner, which involved the exact titanium alloy claims just presented.

The USPTO rejected the claims, alleging a lack of novelty under sections §102(a)and §102 (b), citing a short, highly technical Russian article published in 1970,several years before the Titanium Metals application filing date of July 25, 1975.There was no dispute between the parties that the Russian publication could serve as both a §102(a) reference and a §102(b) reference. The Russian publication disclosed a number of graphs that showed various data points for ternary metal alloys consisting of combinations of titanium, nickel, and molybdenum. From the graphs, it could be discerned that the Russian reference disclosed a metal alloy consisting of 0.25% molybdenum and 0.75% nickel, the balance being titanium, which, as the CAFC noted, falls within the ranges of claim 1 and 2 of Titanium Metals’ application in suit. Applying the patentability/infringement test, the CAFC noted that “there can be no question that claims 1 and 2 read on it and would be infringed by anybody making,using or selling it” (the it being the alloy disclosed in the Russian publication). This relates as an exact analogy to that which we saw previously for the effect of a priorart species falling within a later claimed Markush structure. In fact, one can think of the prior art mixture disclosed in the Russian publication in the Titanium Metals case as a species falling within the claimed ranges of the applicant’s invention.An interesting and important aside to the Titanium Metals case is that the CAFC rejected the plaintiff’s argument that their claimed alloys were patentable because the Russian publication did not disclose the many uses and advantages of the particularalloy disclosed in the plaintiff’s application, such as corrosion resistance to brine.These arguments were to no avail since Titanium Metals’ claim to the alloy simply claims a metal alloy having a certain percent composition, with no limitation to aspecific use. Any metal falling within the range claimed by the plaintiffs is presumed to have such properties since such properties are inherent to the composition itself.

In this vein, the CAFC pointed out that one cannot take something old and make it new for purposes of patenting simply by discovering heretofore undisclosed properties of the old material. Finally, the CAFC did not accept Titanium Metals’ argument that the disclosure of the alloy in the Russian publication was not enabled. Although the publication did not disclose how the particular anticipating alloys were made, the court noted the plaintiff’s specification did not describe the preparation of the alloy either;if the court accepted that the prior art was not enabled then Titanium Metals’ claimedalloys would not be enabled either. In addition, the court noted that applicant’s own expert stated that one of ordinary skill in the art would have known how to prepare the alloys disclosed in the Russian publication by any one of at least three ways.

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