GB784565A - Improvements in or relating to adhesive compositions - Google Patents

Abstract

Thermosetting adhesive compositions comprise (1) 100 parts of a rubbery butadieneacrylonitrile copolymer, (2) 10 to 200 parts of a phenol-aldehyde resin containing reactive phenolic hydroxyl groups, (3) 5 to 100 parts of an epoxide resin, (4) a solvent for (1), (2) and (3), and (5) a sulphur-containing curing system. (2) may be prepared by reacting mononuclear, polynuclear, monohydric and polyhydric phenols, e.g. phenol or cresols, with aldehydes, e.g. formaldehyde, which may first be combined with ammonium hydroxide to form hexamethylenetetramine, in the presence of acidic or basic condensing agents to an intermediate stage such that the products contain phenolic or both phenolic and alcoholic hydroxyl groups. They may be water-, alcohol- or oil-soluble and may be heat-convertible or permanently fusible. (3) may be prepared by reacting polyhydric phenols with between 1 and 2 equivalents of polyfunctional halohydrins, e.g. epichlorhydrin and glycerol dichlorhydrin, in the presence of alkali at least sufficient to react with the halogen of the halohydrin. (4) may be methyl ethyl ketone, acetone and methyl isobutyl ketone. (5) may comprise sulphur or a sulphur-containing curing agent, e.g. tetramethyl or tetraethyl thiuram disulphide, an accelerator, e.g. "Captax" (Registered Trade Mark), and an activator, e.g. zinc oxide. Antioxidants, e.g. di - beta - naphthyl - p - phenylenediamine, may be added. In examples aluminium test panels are bonded by coating with the compositions, allowing to dry and heating under pressure, and copper foil is bonded to phenolic laminates.