Chicago Brand v. Mitutoyo on res judicata
The topic was not unique to patent law, and the law of the regional circuit (here, Ninth Circuit) was applied. (Beech, 990 F.2d 1237 (CAFC 1993)). Elements for res judicata were as presented in Tahoe-Sierra, 322 F.3d 1064 (CA9 2003).
There was a side issue of Rule 11 sanctions.