Prepn of fire retardant resorcinol tetraphenyldiphosphate

Abstract

The preparation process of fire retardant resorcinol tetraphenyl diphosphate includes the first step of the reaction between phenol and phosphorus oxychloride in the presence of Lewis acid catalyst and under heating to produce triphenyl phosphate ester; and second step of ester interchange reaction between triphenyl phosphate ester and resorcinol in the conditions of catalysis, heating and decompression to obtain resorcinol tetraphenyl diphosphate. The reaction temperature is 80-260 deg.c; the catalyst for the first step is Lewis acid catalyst; and the catalyst for the second step is Lewis acid catalyst or alkali catalyst in the amount of 0.05-3 wt% of resorcinol. The acid catalyst is selected from MgCl2, ZnCl2, AlCl3 and TiCl4 and the alkali catalyst is selected from NaOH, KOH, Na2CO3, K2CO3 and sodium phenate. The present invention has the advantages of short reaction period, low power consumption, high product yield and less environmental pollution.

Description

technical field [0001] The invention relates to a preparation method of a flame retardant, in particular to a preparation method of the flame retardant resorcinol tetraphenyl diphosphate. Background technique [0002] Resorcinol tetraphenyl diphosphate is an existing flame retardant. According to the current literature, the synthetic methods reported in the literature mainly contain three kinds: 1. Phosphorus oxychloride reacts with resorcinol to obtain resorcinol tetrachlorobisphosphate, which is then capped with phenol to obtain Target product; 2. Phosphorus oxychloride reacts with phenol to obtain diphenylphosphoryl chloride, then reacts with resorcinol to obtain target product; 3. replace phenol with sodium phenate as raw material, i.e. use sodium phenoxide to resorcinol Tetrachlorobisphosphate was subjected to capping reaction to obtain the product. [0003] Method one, at first, when the first step prepares resorcinol tetrachlorobisphosphate, it is easy to generate p...

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Problems solved by technology

Third, the obtained crude product has a darker color and a higher viscosity, and needs to be washed and decolorized many times, causing serious pollution to the environment.

[0004] Method 2, the pure substance of diphenylphosphoryl chloride is difficult to synthesize, and it is easy to generate the mixture of monophenylphosphoryl chloride, diphenylphosphoryl chloride and triphenylphosphoryl chloride. If diphenylphosphoryl chloride is needed, the mixture needs to be carried out Distillation under reduced pressure, the yield of the product obtained is not high

[0005] Method three, this method reduces energy consumption relative to method one, but the first step reaction is the same as the first step in method one, and there is the same problem, and the preparation of sodium phenate is more difficult because phenol is easily oxidized

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