What is a composition of matter under United States Patent Law?

For a patent application to be granted in the United States the subject of the patent application must fall into at least one of the principle categories of subject matter eligible for a patent. The four principal categories are a process (also termed a method), a machine, an article of manufacture and a composition of matter.

The United States Supreme Court has defined the term composition of matter to includes all compositions of two or more substances and all composite articles, whether they be the results of chemical union, or of mechanical mixture, or whether they be gases, fluids, powders or solids. Diamond v. Chakrabarty, 447 U.S. 303 (1980). Composition of matter claims are considered to be among the most powerful patent claims possible because they are broadly applicable. Composition of matter patent claims cover any use of the claimed composition of matter, unlike process claims which would cover the process claimed in the patent but not necessarily the same process applied to different.

A composition of matter may be protected by a utility patent, but not a design patent.

Some examples of compositions of matter which could be granted a patent include the following:

New drug molecules (i.e., new compounds)
New formulations of known drugs
New drinks or beverages, such as sports drinks, beer, vitamin concoctions, etc.
New food recipes, including new flavors
New materials, such as plastics, metal alloys, etc.

It is important to remember that the above products are the types of products that could be patented as a composition of matter and not a list of things that will be granted a patent. Compositions of matters are still subject to the other rules that control which inventions are eligible for a patent.

The trade off between the broad rights granted in a composition of matter patent is how difficult it is to be granted a composition of matter patent. Patents applications which include composition of matter claims can be rejected by the United States Patent and Trademark Office more easily than other patent applications. Prior art is considered in a much broader sense in composition of matter claims than in the other categories of subject matter eligible for a patent. Prior art is all the information available to the public before a given date that may raise a question of patentability. Normally prior art will prevent a patent application from being granted if the prior art discloses the invention and enables someone skilled in the field to use the invention.

Composition of matter patent claims are scrutinized differently by the United States Patent and Trademark Office. When the prior art and the invention claimed in the patent application are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. The prima facie case of anticipation or obviousness can be rebutted by evidence showing that the prior art products do not necessarily possess the characteristics of the claimed product. So if the prior art discloses a composition with certain properties the applicant must show that the prior art does not necessarily possess the properties of the prior art.

A good examples of what this means is Titanium Metals Corp.v. Banner, 778 F.2d 775, 227 USPQ 773 (Fed. Cir. 1985). In that case claims in a patent application were directed to a titanium alloy containing 0.2-0.4% Mo and 0.6-0.9% Ni, a patent was filed for the alloy because of the corrosion resistance of the alloy. The prior art was a Russian article disclosed a titanium alloy containing 0.25% Mo and 0.75% Ni but did not mention corrosion resistance of the new alloy. The Federal Circuit held that the claim was anticipated because the percentages of Mo and Ni were squarely within the claimed ranges. The court went on to say that it was immaterial what properties the alloys had or who discovered the properties because the composition is the same and thus must necessarily exhibit the properties.

Products of identical chemical composition can not have mutually exclusive properties. A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present.

Getting a patent application granted is not an easy task. A patent application that claims a composition of matter is particularly complex and needs to be carefully drafted. If you have questions about composition of matters claims in a patent application, it if best you consult with an experienced patent attorney.