Hardenable epoxy resin composition

Claim 1

A hardenable epoxy resin composition which contains as essential constituents A. at least one epoxy compound having on the average more than one adjacent epoxy group per molecule and selected from the group consisting of polyglycidyl ethers of polyhydric phenols containing one or more aromatic nuclei, polyglycidyl ethers of alcoholic polyhydroxyl compounds obtained by the addition reaction of polyhydric phenols containing one or more aromatic nuclei with alkylene oxides containing 2 to 4 carbon atoms, and polyglycidyl ethers of alcoholic polyhydroxyl compounds containing one or more alicyclic rings and B. 15 to 35 percent by weight, based on the weight of the epoxy compound (A), of at least one hardener produced by coupling 1. a polyamino condensation product produced by condensing essentially 1-1. phenol (a) having at least one reactive hydrogen atom attached to an aromatic nucleus and selected from the group consisting of phenol, cresol and 2,2-bis(4-hydroxyphenyl)-propane, with 1-2. diamine (b) having at least one active hydrogen atom attached to an amino nitrogen atom per molecule and selected from the group consisting of ethylenediamine, hexamethylenediamine, triethylene tetramine and xylylenediamine, and with 1-3. member (c) selected from the group consisting of formaldehyde and its functional derivatives, in the mole ratio of (a) : (b) : (c) of 1 : 1-3 : 1--3, the condensation reaction mixture being at a temperature lower than 40°C when the member (c) is added, and then the temperature is raised above 40°C to effect a condensation reaction, and 2. alkylphenol (d) selected from the group consisting of cresol and nonylphenol, the ratio of equivalents of phenolic hydroxy groups of alkylphenol (d) : equivalents of active hydrogen atom attached to amino nitrogen atoms of the polyamino condensation product being 0.1 - 1.0 : 1, the coupling reaction being carried out at a temperature of 10°-150°C.