申请人:NIPPON KASEI CHEMICAL CO., LTD.
公开号:EP0937701A1
公开(公告)日:1999-08-25
A process for producing 2,2'-bis(hydroxymethyl)alkanoic acid of the present invention, comprises:
a 2,2'-bis(hydroxymethyl)alkanal production step (A1) of reacting aliphatic aldehyde having two hydrogen atoms bonded to α-carbon atom thereof, with formaldehyde in the presence of a water-soluble base;
a 2,2'-bis(hydroxymethyl)alkanoic acid production step (B) of subjecting the thus obtained aqueous solution (a) containing 2,2'-bis(hydroxymethyl)alkanal and the base to oxidation treatment; and
an alkanoic acid recovery step (C) of separating 2,2'-bis(hydroxymethyl)alkanoic acid from the thus obtained aqueous solution (b) containing the 2,2'-bis(hydroxymethyl)alkanoic acid and the base,
in the alkanoic acid recovery step (C), a mineral acid being added to the aqueous solution (b) in an amount of not more than one equivalent based on the base in the aqueous solution (b) to convert the base into a salt thereof,
water in the aqueous solution (b) being replaced with an organic solvent to form an organic solvent solution, and after removing the mineral acid salt precipitated from the organic solvent solution, 2,2'-bis(hydroxymethyl)alkanoic acid being crystallized from the organic solvent solution.
生产本发明的 2,2'-双(羟甲基)烷酸的工艺包括
2,2'-双(羟甲基)烷醛的生产步骤(A1):在水溶性碱存在下,使其 α-碳原子上键有两个氢原子的脂肪醛与甲醛反应;
2,2'-双(羟甲基)烷酸生产步骤 (B),将由此获得的含有 2,2'-双(羟甲基)烷醛和碱的水溶液 (a) 进行氧化处理;以及
烷酸回收步骤 (C),从由此获得的含有 2,2'-双羟甲基烷酸和碱的水溶液 (b) 中分离出 2,2'-双羟甲基烷酸、
在烷酸回收步骤 (C) 中,向水溶液 (b) 中加入矿物酸,加入量不超过水溶液 (b) 中碱的一个当量,以便将碱转化为盐、
用有机溶剂取代水溶液 (b) 中的水,形成有机溶剂溶液,除去从有机溶剂溶液中析出的矿物酸盐后,从有机溶剂溶液中结晶出 2,2'-双羟甲基烷酸。