Patent

Cyanoacrylate adhesives are widely used for gluing glass, steel, brass, aluminium rubber, "Textolite" (registered Trade Mark), PVC, and other materials, in the aerospace industry, the manufacture of precision instruments, radio-electronics, the manufacture of electronic and optical instrutnents such as photographic cameras and transistor radios, in other branches of technology, and as an adhesive in medicine for soft and osseous tissues.

A method of preparing an α-cyanoacrylate ester of a desired alcohol includes the steps of preparing a compound which is an α-selenoaryl-α-cyanopropionate ester of the desired alcohol, oxidizing said α-selenoaryl-α-cyanopropionate ester to the corresponding selenoxide, eliminating arylselenic acid from the selenoxide to produce said α-cyanoacrylate ester, and separating said α-cyanoacrylate ester from the selenic acid. At temperatures of about 0 occurs concurrently with the oxidizing step using a peroxide or ozone oxidizing agent.

When saturated with boron trifluoride, certain polyhydric alcohols form adducts which catalyze reactions for which boron trifluoride is catalytic. The adduct is recovered from the reaction mixture and recycled, greatly reducing boron and fluoride values in the product and in any effluent. Examples include propylation of toluene in the presence of a recycled adduct of boron trifluoride with mannitol or sorbitol.

An alpha-cyanoacrylate may be formed by first condensing a cyanoacetate with paraformaldehyde or formaldehyde; reacting the polymer formed with an alcohol to transesterify the polymer; and depolymerizing the polymer to form alpha-cyanoacrylate monomers.

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.

The formulations comprise an alkyl C1-C8 cyanoacrylate and an alkyl C1-C8 carboxyacrylate in a proportion from 10 to 30 % by volume with respect to the cyanoacrylate. The alkyl carboxyacrylate of formula (I) is a new product which is obtained from the corresponding cyanoacrylate by hydrolysis with hydrochloric acid. The compositions are packaged in independent containers the content of which is mixed not more than one hour before its use. It can be used in surgery as alternative means for the traditional suture and is specially appropriate in ophthalmics surgery.

A monomer composition comprising at least one polymerizable alkyl ester α-cyanoacrylate monomer.