Ascertaining the differences between prior art and claims at issue requires interpreting the claim language and considering both the invention and the prior art references as a whole.
This blog has previously discussed the effect of several different types of estoppel. See, e.g., Estoppel Estopped for Remanded Claims, Reminder: Estoppel May Not Preclude Prior-Art.
[co-author: Ruben Munoz]
A panel at the Patent Trial and Appeal Board recently considered whether a petitioner was estopped from bringing an
inter partes review (IPR) based on a judgment in a previous interference proceeding.
Mexichem Amanco Holdings owns the patent at issue, U.S. Patent No. 8,633,340, which covers processes for preparing chlorinated and fluorinated hydrocarbons. In September 2020, The Chemours Company (petitioner) filed a petition for IPR seeking review of certain claims of the ’340 patent.
This was not the first time that petitioner had challenged the ’340 patent at the board. In 2018, the ’340 patent was involved in an interference with one of petitioner’s reissue applications. Pursuant to the board’s instruction, each party in the interference submitted a list of motions they intended to file. Notably, while patent owner sought permission to file motions challenging