SiCl_4制备正硅酸乙酯的工艺研究

为寻找一条工序简单、耗价低、易于工业放大路线,实现多晶硅副产物四氯化硅(SiCl4)废物资源化制备正硅酸乙酯(TEOS),本文以多晶硅副产物SiCl4和无水乙醇为原料制备TEOS,在半连续化生产工艺的基础上研究了SiCl4与乙醇的摩尔比、反应温度、反应时间等因素对TEOS产率及纯度的影响。正交实验优化结果表明:15℃下,以恒定速率滴加14.21 g无水乙醇于15 g四氯化硅中,反应35 min,补加8.12 g无水乙醇;55℃下恒温40 min,经减压蒸馏,除去低沸点的乙醇和氯化氢,TEOS产率达到86.61%。对正交实验优水平下制得的产物进行红外光谱(IR)和气相色谱(GC)分析,结果表明:产物中TEOS结构正确,其纯度大于99.0%,达到市售分析纯纯度。

Study on Preparation Technology of TEOS from Silicon Tetrachloride

In this article,tetraethyl orthosilicate （TEOS） was prepared using silicon tetrachloride and alcohol as the raw materials. Effects of the ratio of SiCl4 and alcohol,reaction temperature,reaction time on yield and purity of TEOS were studied based on semi-continuous process.The results of orthogonal experiment indicated：At 15 ℃,14.21 g alcohol at a constant rate was dropped into 15 g SiCl4.After reaction 35 min,8.12 g alcohol was supplemented,then at 55 ℃ constant temperature 40 min.The yield of TEOS was up to 86.61% after removing low boiling point alcohol and hydrogen chloride through vacuum distillation. IR and GC demonstrated that the structure of TEOS was correct and its purity was over 99.0% and reach analytical reagent.