Loctite (Ireland) Limited

Paul Conway

John M Rooney

John G Woods

David P Melody

Francis Richard Martin

Bernard J Bolger

J Eisirt Casey

A curable composition of a vinyl ether resin and at least one ferricenium salt of the formula: ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same or different H or alkyl groups or a linkage to a polymer backbone; M is a metal or metalloid; X is a halide; and n is an integer equal to 1 plus the valency of M.

Ferricenium salt catalysts for vinyl ethers

An anaerobic adhesive composition activatable by ultraviolet or visible radiation is disclosed which forms strong bonds with lapped surfaces and which is comprised of (a) an anaerobically polymerizable acrylate ester monomer, (b) a compound which decomposes upon exposure to ultraviolet or visible light radiation to release a strong acid, (c) a peroxy free radical initiator capable of initiating the polymerization of the monomer upon substantial exclusion of oxygen and (d) an activator of anaerobic polymerization which, in the presence of a strong acid, reacts with the peroxide initiator to produce free radicals to catalyze the anaerobic polymerization of the monomer.

Radiation-activatable anaerobic adhesive composition

Ferricenium salts of the formula: ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same or different H or alkyl groups or a linkage to a polymeric backbone: M is a metal or metalloid; X is a halide and n is an integer, induce polymerization of acrylic monomer/peroxy initiator systems. Above a certain minimum concentration, however, gel time of the composition increases with additional ferricenium salt. This property is especially useful for controlling pot life of an activated acrylic composition.

Acrylic polymerization catalysts containing ferricenium salts

Polymerization of acid activated compositions of acrylic monomers, peroxy initiators and ferrocene derivatives is inhibited by addition of 0.5-20% of a vinyl ether monomer. Bulk compositions activated by addition of a strong acid can be provided with a desired polymerization induction time directly related to the concentration of the vinyl ether. Compositions containing compounds which decompose to a strong acid upon exposure to actinic radiation, thereby activating polymerization, have increased shelf lives when vinyl ethers are included therein. The use of vinyl ether monomers having a functionality of two or more also provides increased adhesive bond strength after curing.

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Bury St. Edmunds, United Kingdom

Paul Conway