2003

ω-(p-Vinylphenyl)alkanols, including methanol, ethanol, propanol, pentanol, and hexanol, have been partially alkoxidated with potassium naphthalene to initiate anionic polymerization of ethylene oxide (EO) in order to directly prepare the corresponding α-p-vinylphenylalkyl-ω-hydroxy poly(ethylene oxide) (PEO) macromonomers. p-Vinylphenylmethanol, i.e. p-vinylbenzyl alcohol (VBA) afforded the expected well-defined macromonomer via living polymerization mechanism and the kinetics have been examined as a function of extent of potassium-alkoxidation.

Ethoxyethyl α-cyanoacrylate was synthesized by first making oligo(ethoxyethyl α-cyanoacrylate) through a condensation reaction of ethoxyethyl cyanoacetate with paraformaldehyde, followed by a depolymerization of the oligomer at an elevated temperature in an acidic atmosphere with a high vacuum. The ethoxyethyl cyanoacetate was in turn synthesized from an esterification of ethoxyethanol and cyanoacetic acid. The molecular structure of the target monomer and the corresponding intermediates were corroborated by IR and 1H-NMR.

Various methacryloyloxymethylalkoxysilanes have been synthesized by nucleophilic substitution reactions starting from chloromethylalkoxysilanes under phase transfer catalysis conditions. The compounds thus obtained show an exceptionally high degree of reactivity with regard to hydrolysis and condensation both under acidic as well as under basic conditions compared to the established 3-methacryloyloxypropyltrimethoxysilane. A mechanistic model for this high reactivity by intramolecular activation is discussed.

The problem addressed by the invention was to find an anionic polymerization inhibitor for cyanoacrylate adhesives containing one or more cyanoacrylates, stabilizers against anionic and radical polymerization and auxiliaries typically used in such adhesive systems which, besides a reliable inhibiting effect, would counteract any increase in the setting time after storage. This problem was solved by using 2-oxo-1,3,2-dioxathiolanes as inhibitors.

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.

Some alkenyl- and alkinyl-2-cyanoacrylate monomers, possessing adhesive properties were synthesized. The ease of esterification of cyanoacetic acid, the first step of the synthesis, with some alcohols was in the following order:

An adhesive composition (I) comprises up to 50 wt.% monomeric 2-alkoxy-alkyl-2-cyanoacrylate and 1-15 wt.% poly(1-5C) alkyl(meth)acrylate having an average mol. wt. of 10,000-60,000. An adhesive composition (I) comprises(with respect to components (A)-(C)): (a) up to 50 wt.% monomeric 2-alkoxy-alkyl-2-cyanoacrylate; (b) 1-15 wt.% poly(1-5C) alkyl(meth)acrylate having an average mol. wt. of 10,000-60,000; (c) 0-10 wt.% hydrophobic pyrogenic silicic acid; (d) 50-10,000 ppm polymerization stabilizer and; (e) 200-10,000 ppm accelerator.

A cyanoacrylate adhesive contains an added ester, the ester used being at least one partial and/or full ester of monobasic or polybasic aliphatic carboxylic acids containing 1 to 5 carbon atoms directly attached to one another and monohydric to pentahydric aliphatic alcohols containing 1 to 5 carbon atoms directly attached to one another, the number of carbon atoms directly attached to one another in the other aliphatic groups being at most three where one aliphatic group contains 4 or 5 carbon atoms.

A composition comprising at least one carrier solvent, at least one primer component and at least one gelling or solidifying agent is provided. The composition according to the invention may he provided in the form of a soft solid, for example, in the form of a stick. A two-part adhesive system is also provided, comprising at least one anaerobic product and a composition comprising at least one carrier solvent, at least one primer component where the primer component is a cure promoting agent and at least one gelling or solidifying agent.

An activator composition for the accelerated hardening of cyanoacrylate adhesives, wherein the activator comprises a member selected from the group consisting of: aromatic heterocyclic compounds having at least one N hetero atom in the ring(s) such as pyridines, quinolines and pyrimidines and substituted on the ring(s) with at least one electron-withdrawing group which decreases the base strength of the substituted compound compared to the corresponding unsubstituted compound, mixtures of any of the foregoing with each other, and/or with N,N-dimethyl-p-toluidine, and mixtures of any of the