| 摘要 |
<p>Compsn. comprises (a) an epoxide cpd. with >=2 1,2-epoxide gps., (b) hardener selected from (i) polyanhydride of m.wt. 1000 comprising the reaction prod. of a maleic monomer and >=1 alkyl styrene monomers and (ii) pre-polymers of (i) and the epoxide, (c) curing catalyst, (d) 55-75 wt. % of a silica filler, (e) 10-20 wt.% calcined clay Sb2O3, Sb tetraoxide, Ca silicate, TiO2, CaCO3, ZnO, MgO or mixts. as additional filler, (f) 0.01-2 wt.% of carnauba wax, montanic acid ester wax, polyethylene wax and/or PTFE wax lubricant, and (g) 0.05-2 wt.% of silane coupling agent. The presence of (e), (f) and (g) improves the high temp. wet electrical props of the compsn., when heat cured, as indicated by a decreased % change of the dielectric loss index measured after exposure to 15 psig steam for 16 hr from the dielectric loss index measured under dry conditions at 25%. Compsns. are used to encapsulate semiconductors.</p> |
