Synthetic method of fire-retardant N,N'-ethylene bis-tetrabromo phthalimide and screw thrust tubular reactor

Abstract

The present invention discloses the synthesis process of fire retardant Nú¼Níõ-ethylene bis-tetrabromo phthalimide and its screw thrust tubular reactor. Inside the screw thrust tubular reactor, phthalic anhydride and ethylene diamine are first condensated under no water condition to synthesize Nú¼Níõ-ethylene bis-phthalimide, and bromine is then dropped to produce bromination in fuming sulfuric acid as solvent and in the presence of multiple phase catalyst so as to produce Nú¼Níõ-ethylene bis-tetrabromo phthalimide. The process may include post-treatment steps of water washing, sand grinding, pressure filtering, stoving, etc. to obtain the target product fine white Nú¼Níõ-ethylene bis-tetrabromo phthalimide powder. It has no color change in high temperature roasting, and may be used in product with high color requirement.

Description

technical field [0001] The invention belongs to a production method of a flame retardant, in particular to an industrial synthesis method of a flame retardant N, N'-ethylene bistetrabromophthalimide. Background technique [0002] N,N'-Ethylene bis-tetrabromophthalimide, molecular formula structure: [0003] [0004] The pure product is white powder, melting point is 450°C, decomposition temperature is above 450°C, density is 2660 kg / m3, solubility (g / 100g, temperature 25°C), in acetone, benzene, o-dichlorobenzene and dimethyl Formamide is less than 0.5, 0.015 in cottonseed oil, and 0.002 in water. It is an efficient additive flame retardant. [0005] Looking at the production and research and development status at home and abroad, the synthesis route of N,N′-ethylene bis-tetrabromophthalimide flame retardant from phthalic anhydride is as follows: [0006] ①First bromination and then organic solvent condensation process [0007] Typical synthesis method of tetrabromopht...

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