GB874245A - Improvements in and relating to epoxide compositions - Google Patents

Abstract

A heat hardenable composition comprises a mixture of a polyglycidyl ether of a polyphenylol having at least three phenylol groups in its molecule linked together by at least one unsaturated aldehyde residue, and a reactive phenol-formaldehyde condensate in an amount sufficient to harden the composition, said polyphenylol being made by the reaction of at least three moles of a monohydric phenol with one mole of an olefinic aldehyde having the formula CnH2n-1CHO where n is 2-6 inclusive in the presence of an acidic catalyst. Specified polyglycidyl ethers are made by reacting the polyphenylol with epichlorohydrin or glycerol dichlorohydrin. Specified phenol-formaldehyde resins are derived from cresols, xylenols or resorcinol. The curing reaction may be promoted by a Friedel-Crafts catalyst alone or in combination with polyhydric alcohols, primary-, secondary-, or tertiary-amines, alkali hydroxides, alkali phenoxides, alkali metal salts of carboxylic acids and quaternary ammonium compounds of which many are specified. The polyglycidyl ether and the phenol-formaldehyde condensate may be blended in the presence of solvents, e.g. ethyl acetate, propyl acetate, butyl acetate, ethyl butyrate, ethyl methyl ketone, diethyl ketone, nitromethane, nitroethane, nitropropane, the monoethyl, monobutyl or monobenzyl ethers of ethylene glycol and mixtures of ethanol, propanol or butanol with toluene or benzene. The exemplified polyglycidyl ether made by reacting epichlorohydrin with a polyphenylol made from phenol and acrolein is mixed with (1) a phenolformaldehyde novolak made in the presence of oxalic acid, ethyl alcohol, toluene and a -methyl benzyl dimethyl amine; (2) a phenol-formaldehyde resole made in the presence of sodium sulphate, ethyl alcohol, toluene and a -methyl benzyldimethylamine; (3) a novolak as in (1), acetone, toluene and a boron trifluoride/ethylamine complex; (4) the resole as in (2) and the solvents and catalyst as in (3) and (5), the novolak as in (1) and the solvents and catalyst as in (3), the solutions being used for impregnating glass weave cloths which are stacked, pressed and cured to form laminates. Specification 788,556 is referred to.ALSO:A triphenylol derivative is made by reacting phenol with aerolein in the presence of concentrated hydrochloric acid. The Specification refers generally to polyphenylols derived from phenols and unsaturated aldehydes CnH2n-1CHO where n is 2 to 6 inclusive. Specification 788,556 is referred to.