1980

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.

Phenolic materials containing propargyl groups are prepared by reacting a polyhydric, phenolic material with propargyl bromide, the reaction being conducted in an aqueous sodium hydroxide solution. The products can be thermally polymerized to polymers which are useful as adhesives and as matrix resins in the fabrication of composites

An adhesive composition comprising a 2-cyanoacrylate and at least one member selected from the group consisting of substituted or unsubstituted aliphatic carboxylic acids having three or more carboxyl groups, anhydrides thereof, partial esters thereof, aromatic polycarboxylic acids having three or more carboxyl groups and anhydrides thereof. This composition has a high impact strength, is suitable for bonding metallic substrates to one another and is also excellent in resistance to heat, weather, and water.

An adhesive composition based on 2-cyanoacrylate esters contains as an anionic polymerization inhibitor an acid chelate formed of boric acid or a derivative thereof and a selected polyhydroxy compound. The chelate is conveniently formed in situ in the 2-cyanoacrylate ester, but may also be prepared separately and added to the ester directly. An exemplary acid chelate used as stabilizer is prepared from boric acid and pyrogallol. The resulting stabilized adhesive compositions have a rapid cure rate and may be used on a wide variety of substrates.

A method wherein uncured urethane formulations are bonded to a cured rubber or synthetic rubber substrate in such a manner so as to provide greater bonding strenght than has been achieved previously in urethane formulation bonding to rubber or synthetic rubber.