632-79-1Relevant articles and documents
Synthesis method of 4-halogenated phthalic anhydride and derivative thereof
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Paragraph 0024; 0028-0029; 0033-0034; 0038-0039; 0043-0044;, (2020/12/30)
The invention relates to a synthetic method of 4-halogenated phthalic anhydride and a derivative of the 4-halogenated phthalic anhydride, and solves the technical problems of low product purity, poorproduct performance, complex synthetic process and low utilization ratio of monohalide isomers and polyhalides in the existing production process. The method specifically comprises the following steps: dissolving phthalic anhydride in an organic solvent, and introducing a halogenating reagent under the action of iron powder and a Lewis acid catalyst to prepare a halogenated phthalic anhydride mixture; rectifying and purifying the polyhalogenated phthalic anhydride mixture to obtain a 4-halogenated phthalic anhydride pure product; and continuing subjecting residual halogenated phthalic anhydride mixture to halogenation reaction under the action of fuming sulfuric acid and the catalyst to prepare tetrahalogenated phthalic anhydride, and to realize comprehensive utilization of the raw materials. The method is widely applied to the technical field of flame retardant synthesis.
Intermediates to tetrabromophthalic anhydride and process therefor
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, (2008/06/13)
Tetrabromophthalic anhydride and the corresponding free acid are propared by oxidizing in the liquid phase a compound of the formula STR1 each of A and A' is independently selected from oxygen, OH or acetoxy; each of R and R' is independently selected from H, OH, alkyl, alkylidene or oxygen; x is 0 or 1; y is 3-x; and Ry and R'y may together form a closed alicyclic or heterocyclic ring structure. Mixtures of two or more compounds of formula (I), optionally in the presence of an oxidation catalyst, can also be employed as the starting material.
Halogenated polyol-ester neutralization agent
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, (2008/06/13)
Haze-free reactive flame retardant halo polyols are made by reacting (a) a halogen containing cyclic acid anhydride (e.g. tetrabromophthalic anhydride), (b) an aliphatic polyol, e.g. diethylene glycol, and (c) an epoxide, e.g. propylene oxide, and including potassium salt of fatty acids (e.g. potassium acetate) in the reaction mixture in an amount at least sufficient to neutralize residual sulfuric acid that is usually present in the halogen containing cyclic acid anhydride.