Technical documentation

An adhesive composition comprising 2-cyanoacrylate and at least one compound selected from the group consisting of R1-CH2OH,

pentafluorophenol, hexachloroacetone, hexachloroacetone hydrate, chloral and chloral hydrate as cationic-polymerization inhibitor. In the above formulas, R1 is a fluorinated alkyl or aryl group having up to 12 carbon atoms, and R2 and R3 are fluorinated or non-fluorinated alkyl or aryl groups having up to 12 carbon atoms. The above adhesive composition has an excellent storage stability and an improved bonding strength.

A curable cyanoacrylate adhesive composition intended for medical and/or veterinary uses is sterilized in liquid form by gamma irradiation. The composition comprises

a) a cyanoacrylate monomer

b) a combination of an anionic stabilizer in amounts effective to stabilize the composition during storage prior to cure, wherein the free radical stabilizer is a selected phenolic antioxidant (but not including hydroquinone).

An adhesive composition based on 2-cyanoacrylate esters contains as an anionic polymerization inhibitor an acid chelate formed of boric acid or a derivative thereof and a selected polyhydroxy compound. The chelate is conveniently formed in situ in the 2-cyanoacrylate ester, but may also be prepared separately and added to the ester directly. An exemplary acid chelate used as stabilizer is prepared from boric acid and pyrogallol. The resulting stabilized adhesive compositions have a rapid cure rate and may be used on a wide variety of substrates.

Cyanoacrylate adhesives contain one or several cyanoacrylic acid esters and stabilisers against anionic and radical polymerisation, as well as auxiliary substances common in such adhesives. The object of the invention is to find an anionic polymerisation inhibitor which counteracts setting time prolongation due to storage while retaining a reliable inhibitor effect. This object is attained by using 2-oxo-1,3,2-dioxathiolanes as inhibitors.