English

Alkyl 2-cyano-2,4-pentadienoates and alkyl 2-cyano-2,4-hexadienoates were synthesized and characterized by spectroscopic methods. These were then evaluated as cross-linkers in 2-cyanoacrylate adhesive compositions to improve the heat stability of their adhesive bonds between various metal surfaces.

This invention relates to modified alpha-cyanoacrylates adhesive compositions and is particularly concerned with alpha-cyanoacrylate compositions containing up to 50% of a polymerizable neutral vinyl monomer admixed with monomeric alpha-cyanoacrylate ester.

2-Allyl-3(5)-pentadecylphenols were synthesized and characterized spectroscopically; their acrylic and methacrylicesters were synthesized. The acrylicester was evaluated as a reactive monomer in u.v.-curable coating compositions and the methacrylicester in anaerobic adhesive formulations. Phenolic resin from 2-allyl-3(5)-pentadecylphenol was prepared and evaluated as a wood bonding adhesive.

The effect of adding various anhydrides, such as succinic, maleic, phthalic, and pyromellitic anhydrides, to alkyl cyanoacrylate on the heat ageing and moisture resistance properties of the adhesive bonds is studied. Such an addition was generally found to improve the adhesion of alkyl cyanoacrylate to metals, in addition to providing other improvements. Maleic anhydride is the only one that appears to act as a crosslinking agent with cyanoacrylate, thus providing improved heat and moisture-resistant bonds.

There are here disclosed an adhesive composition obtained by adding a fluorine-containing carboxylic acid epoxy adduct to a 2-cyanoacrylate, and a process for preparing the adhesive composition. This 2-cyanoacrylate-based adhesive composition is excellent in storage stability and particularly excellent in adhesive force and impact resistance and has a high hardening rate.

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.

A process is described for preparing 2,2,6,6-tetramethylpiperidine-N-oxyl and its 4-position substituted derivatives by oxidation of 2,2,6,6-tetramethylpiperidine and its 4-position substituted derivatives in the presence of hydrogen peroxide and low concentrations of divalent metal salts.

Alicyclic mono and diacrylates from alpha-pinene and beta-pinene were synthesised and characterized spectroscopically. They were compounded in alkyl 2-cyanoacrylate adhesives as crosslinkers. Their effect on the adhesive bond strengths after exposing the adhesive bonds to various temperatures, was studied.

Adhesive properties of β-vinyl-α-cyanoacrylates and their anionic copolymerization with α-cyanoacrylates are studied. The ability of bifunctional β-vinyl-α-cyanoacrylates to enhance the thermal stability of cyanoacrylate adhesives is demonstrated.