Abstract: A process for the manufacture of wire insulation varnish resins suitable for application from the melted state which comprises:1. Contacting a lower alkyl ester of terephthalic acid with tris-(hydroxyethyl)-isocyanurate and ethylene glycol in the presence of a trans esterification catalyst in the presence of 0.3 to 1.5% of an alcoholate of titanium, vanadium or zirconium and effecting transesterification under transesterification conditions;2. Contacting the transesterification product from step 1 with trimellitic acid anhydride under esterification conditions to further effect esterification, but prior to completion of such esterification;3. Adding to the reaction mixture 4,4'-diaminodiphenyl methane in an amount such that the molar ratio of trimellitic acid derived from trimellitic acid anhydride to said 4,4'-diaminodiphenylmethane is 2 to 1; and4. Polycondensing the reaction mixture until a resin is formed having a consistency at 140.degree. to 160.degree.