Method for producing cyclic diesters of L-, D- and D,L-lactic acid

US8431678B2 · kind B2 · utility

Assignee

• Jungbunzlauer Austria AG · AT

Inventors

• Gerald Rafler · Potsdam, DE
• Jutta Rafler · Potsdam, DE
• Andreas Windsperger · Neulengbach, AT
• Robert Edlauer · Thaya, AT
• Josef Gass · Judenburg, AT

Key dates

• Filing date: Nov 14, 2008
• Grant date: Apr 30, 2013
• Expiry date: Aug 30, 2029

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G63/85
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Method for the production of L,L-, D,D-, D,L- and meso-dilactides, comprising the polycondensation and/or polytransesterification of an L-, D- or D,L-lactic acid or of esters thereof to polyesters of higher molecular weights of the L-, D- and D,L-lactic acid (polylactic acids) and cyclizing depolymerization of the polylactic acids to dilactides, wherein the polyesters of higher molecular weights of the L-, D- and D,L-lactic acids are produced in the presence of hydrolysis-stable metal compounds as catalyst.