| 摘要 |
PURPOSE:To easily remove impurities such as PEG dissolved in a reaction liquid obtained by the dehydrobromination reaction using PEG as a phase- transfer catalyst and to produce a ring-brominated styrene monomer having high quality in high efficiency. CONSTITUTION:A ring-brominated beta-bromoethylbenzene is dehydrobrominated by reacting with an aqueous solution of an alkali metal hydroxide in the presence of a PEG (polyethylene glycol) preferably having a molecular weight of 400-1,000 as a phase transfer catalyst at 0-80 deg.C (preferably 20-60 deg.C) to obtain a ring-brominated styrene monomer. The reaction liquid is treated with an ion exchange resin, preferably an MR-type cation exchange resin having styrenic matrix structure and sulfonic acid-type functional group to remove impurities such as modified PEG dissolved in the reaction liquid. The reaction has to be carried out by adding 100-1,000ppm of a polymerization inhibitor such as hindered phenolic compound based on the ring-brominated beta-bromoethylbenzene. |
