Montecatini Edison, S.P.A. (A Corporation of Italy) v. Karl Ziegler, and E. I. Dupont De Nemours and Company (A Corporation of Delaware)

TAMM, Circuit Judge:

This is an appeal from a final order of the United States District Court for the District of Columbia dismissing appellant Ziegler’s counterclaim.

Both parties have filed applications for patents claiming a certain process for homopolymerizing propylene. Two other parties have also filed applications claiming the same process. In order to resolve this conflict, the Patent Office instituted Interference No. 90,833, a proceeding to determine the question of priority of invention. 1 On September 15, 1969, almost ten years after the interference was declared, the Patent Office…