| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for purifying an episulfide compound in order to improve the hue of the episulfide compound as a raw material for a polysulfide cured resin excellent in optical properties and having very high refractive index. SOLUTION: This method for purifying an episulfide compound having in one molecule at least one structural unit of the formula (1), wherein, R1, R2 and R3 are each H or a 1-10C hydrocarbon group 5 comprises the following process: the episulfide compound is dissolved in an organic solvent inert thereto and then subjected to silica gel treatment with a ratio D/L of 0.1-2.0 (D is column diameter; L is column length) and the residence time of the solution in the column system at <=2 h, or active carbon treatment using e.g. active carbon for adsorbing OH-compounds such as saccharides followed by distilling the solvent off to effect removing specific impurities from the crude episulfide compound and thereby affording the objective pure episulfide compound with improved hue.
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