Onium borates/borates of organometallic complexes and cationic initiation of polymerization therewith

In a process for the cationic initiation of polymerization or crosslinking of functional polymers or monomers via photochemical or electron beam activation, the improvement which comprises, as the cationic initiator therefor, an onium borate, the cationic moiety of which having the formula (I):

• [(R.sup.1).sub.n --A--(R.sup.2).sub.m ].sup.+ (I)
• in which A is an element of Groups 15 to 17 of the Periodic Table;
• R.sup.1 is a C.sub.6 -C.sub.20 heterocyclic or carbocyclic aryl radical;
• R.sup.2 is R.sup.1 or a linear or branched C.sub.1 -C.sub.30 alkenyl or alkyl radical, or such alkenyl or alkyl radical bearing at least one C.sub.1 -C.sub.25 alkoxy, C.sub.1 -C.sub.25 alkyl, nitro, chloro, bromo, cyano, carboxyl, ester or mercapto substituent;
• n is an integer ranging from 1 to v+1, with v being the valence of A;
• and m is an integer ranging from 0 to v-1, with the proviso that n+m=v+1;
• and the anionic borate moiety of which having the formula:
• [BX.sub.a R.sub.b ].sup.-
• in which a and b are integers ranging from 0 to 4 and a+b=4;
• the symbols X are each a halogen atom when a ranges up to 3 and an OH functional group when a ranges up to 2;
• and the symbols R, which may be identical or different, are each a phenyl radical substituted by at least one electron-withdrawing substituent or by at least two halogen atoms, or an aryl radical containing at least two aromatic ring members, or such aryl radical bearing at least one electron-withdrawing substituent.

In a process for the cationic initiation of polymerization or crosslinking of functional polymers or monomers via photochemical or electron beam activation, the improvement which comprises, as the cationic initiator therefor, an onium borate, the cationic moiety of which having the formula (II):

• (L.sup.1 L.sup.2 L.sup.3 M).sup.q+ (II)
• in which M is a metal of Groups 4 to 10 of the Periodic Table;
• L.sup.1 is a ligand associated with the metal M via .pi. electrons and comprising an .eta..sup.3 -alkyl, .eta..sup.5 -cyclopentadienyl or .eta..sup.7 -cycloheptatrienyl ligand or an .eta..sup.6 -aromatic compound selected from among the optionally substituted .eta..sup.6 -benzene ligands and compounds having from 2 to 4 condensed ring members, each ring member contributing to the valence shell of the metal M via 3 to 8 .pi. electrons;
• L.sup.2 is a ligand associated with the metal M via .pi. electrons and comprising an .eta..sup.7 -cycloheptatrienyl ligand or an .eta..sup.6 -aromatic compound selected from among the optionally substituted .eta..sup.6 -benzene ligands and compounds having from 2 to 4 condensed ring members, each ring member contributing to the valence shell of the metal M via 6 or 7 .eta. electrons;
• and L.sup.3 represents from 0 to 3 identical or different ligands associated with the metal M via .sigma. electrons and comprising CO and NO.sub.2.sup.+ ligands, the total electron charge q of the complex to which L.sup.1, L.sup.2 and L.sup.3 contribute and the ionic charge of the metal M being positive and equal to 1 or 2;
• and the anionic borate moiety of which having the formula:
• [BX.sub.a R.sub.b ].sup.-
• in which a and b are integers ranging from 0 to 4 and a+b=4;
• the symbols X are each a halogen atom when a ranges up to 3 and an OH functional group when a ranges up to 2;
• and the symbols R, which may be identical or different, are each a phenyl radical substituted by at least one element or electron-withdrawing substituent.