1976

The disclosed compounds are adducts of imidazole or derivatives thereof and sulfur dioxide. The adducts are apparently of the Lewis acid-Lewis base type, and are useful as latent curing agents for epoxide resins. The adducts are prepared by interacting the imidazole and sulfur dioxide under anhydrous conditions. Equimolar imidazole-SO2 adducts can serve as a source of sulfur dioxide at room temperature.

The disclosed compounds are adducts of imidazole or derivatives thereof and sulfur dioxide. The adducts are apparently of the Lewis acid-Lewis base type, and are useful as latent curing agents for epoxide resins. The adducts are prepared by interacting the imidazole and sulfur dioxide under anhydrous conditions. Equimolar imidazole--SO.sub.2 adducts can serve as a source of sulfur dioxide at room temperature.

New polymerizable adhesive compositions comprising a monomeric ester of .alpha.-cyanoacrylic acid and a difunctional monomeric cross-linking agent which is a diester of acrylic or methacrylic acid and an alcohol having at least two esterifiable hydroxyl group, are found to develop increased cohesive bond strength upon polymerization. The compositions, if desired, can contain a finely divided aggregate, preferred aggregates being alumina and quartz. In addition, the compositions can advantageously contain sodium fluoride.

Carbalkoxyalkyl 2-cyanoacrylates having the formula: ##STR1## wherein R is an organic radical and R' is hydrogen or methyl polymerize rapidly in the presence of moisture and are useful as adhesives. When applied as tissue adhesives in surgical applications, such carbalkoxyalkyl 2-cyanoacrylates cause a minimum of tissue reaction and the resulting polymer is absorbable in mammalian tissue.