The invention discloses composite
epoxy resin resistant to damp-heat aging and a preparation method and application thereof, and belongs to the technical field of
electrical equipment insulating materials. The composite
epoxy resin is prepared by the following steps: preparing an
epoxy resin mixture from
bisphenol A
diglycidyl ether type epoxy resin and N, N, N ', N'-tetraepoxypropyl-4, 4 '-diaminodiphenylmethane according to a
mass ratio of (1.5-4): 1, and reacting the epoxy resin mixture with a methylhexahydrophthalic anhydride curing agent with a specific
molar ratio and a 2, 4, 6-tri (dimethylaminomethyl)
phenol accelerant with a certain amount. Through collaborative optimization of the components and the process, the glass-
transition temperature, bending strength and breakdown
field strength of the epoxy resin are remarkably improved, and the
dielectric loss is effectively reduced, so that the epoxy resin shows excellent
thermal stability,
mechanical property retention rate and insulation reliability in a high-temperature and high-
humidity environment; the method is especially suitable for manufacturing insulation parts of
electrical equipment in coastal and other high-
humidity areas.