The invention relates to an organic
silicon episulfide resin and a preparation method thereof. The preparation method comprises the steps of: mixing organic
silicon epoxy resin with deionized water,
ethanol and
potassium thiocyanate or thiocarbamide, and reacting the mixture at temperature of 15-45 DEG C for 12-36 hours; and after reaction is finished, adding
organic solvent so as to divide the reacted mixture into two
layers, separating out and washing an organic phase to be neutral, adding
anhydrous sodium sulfate into the organic phase, and
drying for 5-15 hours, filtering to remove sodiumsulfate, and removing the
organic solvent at 2-10mmHg / 45-60 DEG C, thus obtaining organic
silicon episulfide resin with the following structure. The organic silicon
episulfide resin has the advantages of lower
viscosity, high purity, high cure reaction activity, high
refractive index, small heat release amount during condensate reaction, high
glass transition temperature, low water
absorption rate, and the like, thus being expected to be applied in the fields
coating, adhesives, electronic device packaging,
composite material matrix resin and the like.