PURPOSE: The titled composition, consisting of a specific epoxy resin, trimellitic acid anhydride, 1,8-diaza-bicyclo[5.4.0]undecene-7, etc., having a specific particle diameter and improved moisture resistance and electrical characteristics at high temperatures, etc., and usable for insulating coating of electric and electronic parts.

CONSTITUTION: An epoxy resin powder coating material composition, obtained by incorporating (A) 100pts.wt. epoxy resin having 180W2,000 epoxy equivalent and 40W150°C melting point, e.g. bisphenol A glycidyl ether type epoxy resin, with (B) 5W20pts.wt. acid anhydride based curing agent consisting of one or more of trimellitic acid anhydride, pyromellitic acid anhydride and benzophenonetetracarboxylic acid anhydride, (C) 0.05W2pts.wt. curing accelerator consisting of one or more of 1,8-diaza-bicyclo[5.4.0]undecene-7 and derivatives thereof and (D) 50W200pts.wt. inorganic filler, e.g. silica powder, and having 30W80μm average particle diameter.

EFFECT: Improved heat cycle resistance.