Technical documentation

a-cyanoacrylate compounds expressed by the following general formula: wherein R' desianates- and R2 designates alkyl groups, alkenyl groups or alkynyl groups of C1 to C4. These compounds are preferably synthesized by the reaction of the compounds expressed by the following general formula: wherein R' and R2 are same as the above described, with formaldehyde products and then the depolymerization of the resulting dehydrating condensation polymers. These compounds are effectively used as fast-setting adhesives.

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.

This invention is related to the preparation of alkyl or alcoxyalkyl-&agr;-cyanoacrylates in monomeric form by depolymerisation of the corresponding poly(alkyl-&agr;-cyanoacrylates) or poly(alcoxyalkyl-&agr;-cyanoacrylates) (PCA). The PCA's are obtained preferably by base-catalyzed condensation of a cyanoacetate with formaldehyde (or a polymer of the latter).

2,4-Dicyanostyrene(DCS)wassuccessfullypreparedin18%yieldviaaseriesofsixreactions and 2,4,6-tricyanostyrene (TCS) was barely in 0.15% yield via five reaction steps. It was found that DCS and TCS are polymerizable with radical and anionic initiators.