Patent applications are complex legal documents, and preparing and filing one requires a large sum of money in terms of attorney’s fees and government fees. What’s often lost in the process is the large amount of time needed from the inventors when preparing the application and participating in the patenting process.
Nothing is worse than investing large sums of inventor time and money on a patent application only to have it rejected or having a patent that is unenforceable.
Below I give a short introduction to the various parts of a patent application and discuss ways to avoid the six most common fatal errors battery and chemical patent cases encounter either during the application process or when trying to enforce a granted patent.
Opening comments
Battery patent applications consist of three distinct sections:
- A description of the invention and how it’s used
- Examples of various characterisation and performance tests performed by the inventors
- The claims
Sometimes applicants include drawings such as cycle life test results, X-ray diffraction data or illustrations of the battery construction.
The claims outline the scope of patent protection the applicant is requesting from the patent office. Within certain limits, the claims can be amended during the application process.
However, the description of the invention and examples may not be amended after a patent application is filed, except in very limited circumstances (e.g. grammatical or other obvious errors).
Common errors in applications
Below is a short list of fatal errors easily dealt with during the application drafting process. The list below is based on my experience and representative, not exhaustive.
#1 – Fail to clearly define test methods
When I’m reviewing a final draft of a patent application, I go through each claim and circle every instance where a unit of measurement is used. I then go back into the description/examples to see if we defined how to measure the physical or performance property associated with the unit of measurement.
Unfortunately, many granted patents suffer because:
- The method to measure the property is not described and there is no test method known in the industry
- The method to measure the property is not described and there are several conflicting methods known in the industry that give differing results
- The description of the test protocol is incomplete
Patents lacking a clear description of critical test protocols result in third parties being unable to test their own products to determine whether their activities could be deemed infringing. As a matter of public policy, members of the public need to be able to discern whether their activities could be deemed to infringe the claims of a patent.
This issue has resulted in a patent application not being granted by a patent office, or a granted patent later being invalidated as being unenforceable.
#2 – Relying on test methods having a high margin of error
Not only should patents clearly outline how to measure chemical and performance properties, but the test methods should also yield relatively reproducible results.
I remember an instance where a patent application claimed an inorganic material having a unique physical property measured by a standard American Society for Testing and Materials (ASTM) method. The ASTM protocol stated: “This method is not reproducible.” Based on the ASTM document, the patent office deemed the disclosure to be insufficient and rejected the application. It was a fatal mistake.
#3 – Fail to properly identify the actual test method used by the inventors
Inventors often reference third party publications (e.g. journals, patents, ASTM publications) to identify the test methods they used to measure a particular property. However, test methods are rarely static.
The following is a common occurrence. While helping a client a third party patent described a new chemical material as having a unique physical property measured “using the method published by Dr Z.” Problem was, prior to the filing of the patent application, Dr Z described different and conflicting ways to measure the property at issue. One method put my client outside the claim scope another put my client inside the claim scope.
The same goes for published standardised test methods such as ASTM methods. I’ve seen patents claiming new chemicals and batteries having properties as determined by a standard ASTM method, e.g. ASTM E1756-08(2015). However, when one looks at the examples where the properties were measured and reported, it’s clear the ASTM method recited in the claims was not used in the experiments. Older versions of ASTM methods might yield different results than their more current counterparts.
If the patent office does not catch this mistake, I can assure you opposing counsel will in a litigation setting.
#4 – Use open-ended numerical ranges
A single numerical value is almost never recited in a claim to quantify a unique property for a new chemical (e.g. a cathode material having a capacity of 230.2mAh/g). Instead, applicants claim a range of numerical values when quantifying chemical properties (e.g. a cathode material having a capacity of between 200 and 300mAh/g, inclusive).
However, problems arise when open-ended ranges are used (e.g. a cathode material having a capacity of at least 230.2mAh/g).
First, in some countries, this is a fatal mistake from the outset. Many countries will simply reject a patent application claim unless it has closed range.
Second, if the top or bottom end of an open range is too speculative or unreasonable, a patent office, or an accused infringer, will certainly argue such values put the claimed invention outside the realm of existing science.
#5 – Fail to define terms
Undefined terms become fodder for arguments during litigation. Terms that may have a clear and ordinary meaning to one chemist may have a different meaning to another.
Terms even as simple as “alkyl” are often defined. If a determination of infringement turns on whether the term “alkyl” includes linear but not branched substituents, you can bet both sides will have opposing expert views.
The term “substantially” is often used in patents (e.g. wherein the reaction mixture is substantially free of Na). The term is mostly ambiguous. While often used in the US, most foreign countries prohibit the use of this term. I use the term in my patent applications. However, I provide both a qualitative and quantitative definition for the term.
#6 – Fail to give comparative data
This is the most important point. After the patent application is filed, the patent examiner will compare the invention against what’s in the public domain. This makes achieving patent protection difficult. Often, the examiner will make an apples-to-oranges comparison. Therefore, if an application’s examples can show how different the new technology is from existing technologies, this could be a good thing. But that’s something to discuss with the attorney.
Closing arguments
