Activators for the polymerization of pyrroldione

Claim 1

A PROCESS FOR POLYMERIZING PYROLIDONE WHICH COMPRISES FORMING UNDER ESSENTIALLY ANHYDROUS CONDITIONS A MIXTURE CONTAINING MONOMERIC PYRROLDIDONE, A CATALYST SELECTED FROM THE GROUP CONSISTING OF ALKALI METALS, PYRROLIDONE SALTS OF ALKALI METALS, HYDRIDES OF ALKALI METALS AND ALKALI METAL ALKYLS AND ARYLS, AND A POLYMERIZATION ACTIVATOR SELECTED FROM THE GROUP CONSISTING OF THE TRIHALIDES OF ALUMINUM, BISMUTH AND ANTIMONY, THE TETRAHALIDES OF TIN, TITANIUM, ZIRCONIUM AND LEAD, AND THE PENTAHALIDE OF ANTIMONY, SAID CATALYST BEING EMPLOYED IN A RANGE OF 0.002 TO 0.25 CHEMICAL EQUIVALENTS OF CATALYST, SAID CHEMICAL EQUIVALENTS BEING BASED UPON THE GRAM MOLECULAR WEIGHT OF SAID CATALYST DIVIDED BY THE VALENCE OF THE METAL IN THE CATALYST BASED UPON ONE MOLE OF MONOMERIC PYRROLIDONE, AND SAID ACTIVATOR BEING EMPLOYED IN A RANGE OF 0.0001 TO 0.075 CHEMICAL EQUIVALENTS OF ACTIVATOR, SAID CHEMICAL EQUIVALENTS BEING BASED UPON THE GRAM MOLECUALR WEIGHT OF THE ACTIVATOR DIVIDED BY THE NUMBER OF HALOGEN ATOMS IN THE ACTIVATOR BASED UPON ONE MOLE OF MONOMERIC PYRROLIDONE WITH A SLIGHT EXCESS OF CATALYST OVER ACTIVATOR BEING PRESENT IN SAID MIXTURE, AND SUBJECTING SAID MIXTURE TO A TEMPERATURE IN A RANGE OF -70*C. TO 100*C.