申请人:Asahi Kasei Chemicals Corporation
公开号:EP1803704A1
公开(公告)日:2007-07-04
It is an object of the present invention to provide a specific process that enables a high-purity diaryl carbonate that can be used as a raw material of a high-quality and high-performance polycarbonate to be produced stably for a prolonged period of time on an industrial scale of not less than 1 ton / hr using as a starting material a reaction mixture containing an alkyl aryl carbonate obtained through a transesterification reaction between a dialkyl carbonate and an aromatic monohydroxy compound. Although there have been various proposals regarding processes for the production of reaction mixtures containing aromatic carbonates by means of a reactive distillation method or the like, these have all been on a small scale and short operating time laboratory level, and there have been no disclosures on a specific process or apparatus enabling mass production on an industrial scale from such a reaction mixture of a high-purity diaryl carbonate that can be used as a raw material of a high-quality and high-performance polycarbonate. According to the present invention, there is provided a specific process that enables a high-purity diaryl carbonate substantially not containing intermediate boiling point by-products or high boiling point by-products and important as a raw material of a high-quality and high-performance polycarbonate to be produced stably for a prolonged period of time on an industrial scale of not less than 1 ton / hr by taking as a starting material a reaction mixture containing an alkyl aryl carbonate that has been obtained through a transesterification reaction between a dialkyl carbonate and an aromatic monohydroxy compound and subjecting this starting material to a transesterification reaction using a reactive distillation column, and then subjecting a high boiling point reaction mixture obtained from the bottom of the reactive distillation column to separation / purification by distillation using a high boiling point material separating column A, a diaryl carbonate purifying column B and an intermediate boiling point material separating column C in this order, wherein each of these three columns comprises a specified continuous multi-stage distillation column, the high-purity diaryl carbonate being obtained as a side cut component from said purifying column B.
本发明的目的在于提供一种特定的工艺,该工艺能够使用含有烷基芳基碳酸酯的反应混合物作为起始材料,通过酯交换反应稳定地在工业规模下生产高纯度的二苯基碳酸酯,该二苯基碳酸酯可用作高质量和高性能聚碳酸酯的原材料,生产规模不少于1吨/小时。尽管已经有各种关于通过反应蒸馏法等方法生产含芳香族碳酸酯的反应混合物的提议,但这些提议都是在小规模和短时间的实验室水平上进行的,没有披露具体的工艺或设备,使得可以从这样的反应混合物中大规模生产可用作高质量和高性能聚碳酸酯的原材料的高纯度二苯基碳酸酯。根据本发明,提供了一种具体的工艺,该工艺使用通过二甲基碳酸酯和芳香族单羟基化合物的酯交换反应得到的烷基芳基碳酸酯作为起始材料,通过使用反应蒸馏柱进行酯交换反应,然后通过使用高沸点物质分离柱A、二苯基碳酸酯净化柱B和中间沸点物质分离柱C依次进行蒸馏分离/净化,从净化柱B中获得高纯度的二苯基碳酸酯作为副产物。该工艺能够稳定地在工业规模下生产高纯度的二苯基碳酸酯,该二苯基碳酸酯基本不含有中间沸点副产物或高沸点副产物,是高质量和高性能聚碳酸酯的重要原材料。