申请人:E.I. DU PONT DE NEMOURS AND COMPANY
公开号:EP0628533A1
公开(公告)日:1994-12-14
This invention is a method for recovering hydroxy acid values from a poly(hydroxy acid) containing source, said method comprising, in order:
(a) contacting the source with a solubilizing fluid in an amount of at least 1 mole of solubilizing fluid per mole of hydroxy acid equivalent present in the source, said solubilizing fluid selected from the group consisting of (1) water, (2) alcohols containing 1 to 6 carbon atoms, (3) mixtures of water and said alcohols, (4) amines of the formula HNR₁R₂, wherein R₁ and R₂ are independently selected from the group consisting of hydrogen and alkyl groups of 1-4 carbon atoms; (5) liquid media containing diamines of the formula H(R₃)NR₅N(R₄)H, wherein R₃ and R₄ are independently selected from the group consisting of hydrogen and alkyl groups of 1-4 carbon atoms or are joined to form a heterocyclic ring, and R₅ is alkylene of 2-12 carbon atoms or phenylene; and (6) mixtures of said amines and/or diamines with water and/or alcohols containing 1 to 6 carbon atoms.
本发明是一种从含有聚羟基酸的源中回收羟基酸值的方法,该方法依次包括:(a)将源与溶解液接触,其量至少为源中每个羟基酸当量的1摩尔的溶解液,所述溶解液选自以下组合:(1)水,(2)含有1-6个碳原子的醇,(3)水和所述醇的混合物,(4)式为HNR₁R₂的胺,其中R₁和R₂分别选自氢和1-4个碳原子的烷基组成的群;(5)含有式为H(R₃)NR₅N(R₄)H的二胺的液态介质,其中R₃和R₄分别选自氢和1-4个碳原子的烷基组成的群,或结合形成杂环环,而R₅是2-12个碳原子的亚烷基或苯亚烷基;(6)所述胺和/或二胺与含有1-6个碳原子的水和/或醇的混合物。