申请人:FERRO CORPORATION
公开号:EP0047549A2
公开(公告)日:1982-03-17
The present process is one for the production of brominated styrene oligomers and polystyrene, preferably what are essentially tribrominated polystyrenes.
One preferred embodiment of the process can be summarized as consisting of:
1. dissolving polystyrene having a molecular weight of at least 20,000 in a solvent and
2. reacting the dissolved polystyrene with a stoichiometric excess of bromine chloride over that required for achieving the desired degree of bromination in the presence of up to about 15% by weight of the polystyrene of a Lewis acid catalyst at about 20°C to about 50°C.
The dominant substitution pattern in the trihalogenated product is at the 2,4,5 positions, with significantly lesser amounts of other isomers including 2,3,5. There does not appear to be any 2,4,6 substitution. A very small percentage of chlorine is believed to be nuclear bound.
本工艺是生产溴化苯乙烯低聚物和聚苯乙烯的工艺,最好是生产基本上属于三溴 化聚苯乙烯的工艺。
该工艺的一个优选实施方案可概括为:
1. 将分子量至少为 20,000 的聚苯乙烯溶解在溶剂中, 2.
2. 在约 20°C 至约 50°C 的温度下,在路易斯酸催化剂的存在下,使溶解的聚苯乙烯与达到所需溴化程度所需的溴氯化物的过量进行反应,溴氯化物的过量以聚苯乙烯重量计最多约为 15%。
三卤化产品中的主要取代形式是 2、4、5 位,其他异构体(包括 2、3、5)的数量明显较少。似乎不存在任何 2,4,6 取代。据信只有极少量的氯与核结合。