Abstract: An epoxy resin, useful for coating the internal surface(s) of a reactor such as one used for vinyl halide, particularly vinyl chloride, polymerisation in aqueous dispersion for the purpose of suppressing build-up, is made by cross-linking (I) the uncross-linked polyether intermediate of an epoxy resin, by admixture with (II) a product made from the reaction of (A) at least one aliphatic amine containing two or more primary aliphatic amino groups, (B) at least one aromatic amine containing two or more primary aromatic amino groups, and (C) at least one compound selected from oxo-group substituted aromatic compounds and quinone-type compounds, wherein the molar ratio (A):(B) is 4:1 to 1:3.Preferably, (I) is made from the reaction between 2,2-bis-(4-hydroxyphenyl) propane and epichlorohydrin and (II) is made from the reaction of (A) tetraethylenepentamine, (B) p-phenylene diamine, and (C) hydropquinone and pyrogallol.