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.
Patent owner Mexichem Amanco Holdings owns 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 both priority and patentability of
petitioner's reissue claims, petitioner only included a single
motion for
