Adhesive composition containing polyepoxide materials

An adhesive composition contains a glycidyl polyether of a dihydric phenol having a Durrans' mercury melting-point below 30 DEG C. and a 1,2-epoxy equivalency of 1.6-2.0 with 3-20 per cent of a second glycidyl polyether of a dihydric phenol with a melting-point above 75 DEG C. and an epoxy equivalence of 1.2-1.8. The first polyether contains 1-1.5 aromatic radicals and the second at least 4. A liquid aliphatic polyepoxide, e.g. bis-(2,3-epoxypropyl) ether or thioether; 1,2-bis-(2,3-epoxypropyloxy) ethane; glycidyl ethers of polyhydric alcohols such as glycerol, diethylene glycol, pentaerythritol or polyally alcohol; or epoxidized drying oils as described in U.S.A. Specification 2,485,160, may also be present. The polyethers are prepared by heating epichlorohydrin or glyceryl dichlorohydrin with resorcinol, 1,1-bis (4-hydroxyphenyl) ethane, propane, butane or 2-ethylhexane, 2,2-bis (4-hydroxyphenyl) propane or butane, 3,3-bis (4-hydroxyphenyl) pentane or the isomeric 2,41-and 2,21 dihydroxy phenyl compounds, and with sodium hydroxide. The two polyethers may be prepared from the same or different phenols. The higher molecular weight polyether may be made by reacting a lower molecular weight one with more polyhydric phenol. Preferably the powdered high-melting polyether is dissolved in the molten low-melting one, and the liquid aliphatic polyepoxide added if desired for thinning. Nitriles, e.g. aceto-, propio-, butyro-, capro-, lauro-, acrylo-, methacrylo-, croto-, oleo-, succino-, glutaro-, adipo-, or fumaro-, may also be added to reduce the viscosity of the mixture. Fillers which may be added are asbestos, aluminium oxide, iron oxide, silica, bauxite, zinc oxide, china clay, titanium oxide and silicon carbide. Suitable hardening agents are alkaline, e.g. sodium hydroxide or phenoxide, acids, e.g. formic, oxalic, phthalic, phosphoric or partial phosphates, e.g. diethyl orthophosphate, hexaethyl tetraphosphate, Friedel-Crafts' catalysts or complexes thereof, and amino compounds, e.g. triethylamine, ethylene diamine, pyridine, N,N-diethyl - 1,3 - propanediamine, dicyandiamide, melamine or others. The preparation of a number of specific polyethers is described, together with the preparation of compositions containing them and the use of those compositions as adhesives particularly for joining metals.