NOVEL CRYSTAL FORM OF 4,4'-BIS(2,3-DIBROMOPROPOXY)-3,3',5,5'-TETRABROMODIPHENYL SULFONE AND PRODUCTION METHOD THEREFOR

摘要

Provided are a novel crystal form of 4,4'-bis(2,3-dibromopropoxy)-3,3',5,5'-tetrabromodiphenyl sulfone having excellent thermal stability and a high melting point and a method for producing the crystal form.　A crystal form (II-form crystals) of 4,4'-bis(2,3-dibromopropoxy)-3,3',5,5'-tetrabromodiphenyl sulfone is provided. The II-form crystals can be produced by applying a shear force to existing intermediate-melting-point crystals (I-form crystals).