Abstract: A process for the production of polylactide, the stages of which for the production and purification of lactide, starting from an aqueous solution of lactic acid or of its derivatives, includes evaporation of water with formation of oligomers, depolymerization to give lactide, condensation and then crystallization of the crude lactide product to give purified lactide, aqueous treatment of the residual fractions from the crystallization and polymerization of purified and/or prepurified lactide to give polylactide in an extruder and in the presence of catalysts. An alternative process includes carrying out the aqueous treatment before the crystallization.
Type:
Grant
Filed:
August 4, 2003
Date of Patent:
February 10, 2009
Assignee:
Brussels Biotech
Inventors:
Philippe Coszach, Jean-Christophe Bogaert, Frederic Van Gansberghe
Abstract: The invention concerns a method for purifying the dimeric cyclic esters of lactic (or glycolic) acid starting from a raw lactide (or glycolide) comprising impurities, the method consisting in: extractive and controlled crystallization of the raw lactide, in aqueous medium, controlling the geometry of the formed crystals and carrying out a separation of phases into lactide and impurities; separation of the resulting suspension of crystals, into a phase poor in lactide and loaded with impurities, and a wet cake rich in lactide crystals; drying the resulting wet cake; and recrystallization in melted medium of the resulting dried impure lactide and recuperating the purified lactide.
Type:
Grant
Filed:
January 13, 2003
Date of Patent:
October 5, 2004
Assignee:
Brussels Biotech
Inventors:
Frédéric Van Gansberghe, Philippe Coszach, Patricia Di Salvatore, Jean-Christophe Bogaert
Abstract: The invention concerns a method for recuperating and purifying a lactic acid solution obtained initially from a fermentation medium or any other source, consisting in a pre-treatment to eliminate the ion loads capable of catalysing the lactic acid condensation and based on the principle of ion exchange or any other related principle, followed by at least a step of concentration at low temperature and brief retention time and at least a step of distilling the lactic acid using a thin layer process.
Type:
Grant
Filed:
November 2, 1999
Date of Patent:
December 3, 2002
Assignee:
Brussels Biotech
Inventors:
Frederic Van Gansbeghe, Jean-Christophe Bogaert, Etienne Malhaize, Martin Van Gansberghe, Florence Wolff
Abstract: An aliphatic polyester and/or copolyester, obtained from a polyreaction of at least one monomer from the group comprising lactides, lactones, cyclic carbonates and cyclic anhydrides. To be able to prepare the aliphatic polyester and/or copolyester a reaction mixture is used which contains at least one catalyst of the general formula (M) (X.sub.1, X.sub.2 . . . X), M being a metal selected from the group 3 to 12 of the periodic system (X.sub.1, X.sub.2 . . . X.sub.m) being a substituent selected from one of the families of alkyls, aryls, oxides, carboxylates, halogenides, alkoxides and compounds with elements from group 15 and/or 16 of the periodic system, m being an integer in the range of from 1 to 6, and n being an integer in the range of from 0 to 6, and which also contains a co-catalyst of the general formula (Y) (R.sub.1, R.sub.2 . . . R.sub.q).sub.p, Y being an element selected from the group 15 or 16 of the periodic system. (R.sub.1, R.sub.2 . . . R.sub.
Type:
Grant
Filed:
January 15, 1999
Date of Patent:
December 26, 2000
Assignee:
Brussels Biotech
Inventors:
Hans-Gerhard Fritz, Sven Jacobsen, Robert Jerome, Philippe Degee, Philippe Dubois