Mixtures

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.

Various alkyl2-bromoacrylates were synthesized in high purity and yield. They were characterized by spectroscopic techniques. The monomers were then formulated into aerobic adhesive compositions and their adhesive bond strengths between various surfaces were evaluated.

A cyanoacrylate adhesive composition having an acrylic monomer toughening agent. Preferably, the acrylic monomers are selected from the group consisting of methyl methacrylate, butyl acrylate, cyclohexyl acrylate, isobornyl acrylate, and combinations thereof. A useful amount of acrylic monomers is about 1.0% by weight to about 10.0% by weight, preferably about 1.0% by weight to about 5.0% by weight, and more preferably about 2.0% by weight to about 5.0% by weight.

A process for the preparation of esters, including non-distillable esters, of 2-cyanoacrylic acid comprises reacting 2-cyanoacrylic acid or an acid halide thereof with an alcohol, including a diol or polyol, or a phenol in the presence of an inert organic solvent under polymerisation inhibiting conditions and, additionally, in the presence of an acid catalyst when 2-cyanoacrylic acid is a reactant, continually removing the water or hydrohalic acid produced and recovering the ester.

A process for the preparation of 2-cyanoacryloyl chloride in pure form comprises reacting 2-cyanoacrylic acid with a chlorinating agent, said reaction being carried out under side-reaction and polymerisation inhibiting conditions. A preferred chlorinating agent is a volatile chlorinating agent which forms only volatile by-products during the course of the reaction. Suitable volatile chlorinating agents include oxalyl chloride, sulfur oxychloride, trifluoroacetyl chloride and phosgene.