US 12,351,678 B2
Process for preparing stabilized aliphatic polyester, and compositions obtained therewith
Gerrit Gobius Du Sart, DA Herwijnen (NL); and Wilko De Lang, Utrecht (NL)
Assigned to TotalEnergies Corbion B.V., Gorinchem (NL)
Appl. No. 17/616,032
Filed by TotalEnergies Corbion B.V., Gorinchem (NL)
PCT Filed May 29, 2020, PCT No. PCT/EP2020/065066
§ 371(c)(1), (2) Date Dec. 2, 2021,
PCT Pub. No. WO2020/245063, PCT Pub. Date Dec. 10, 2020.
Claims priority of application No. 19177894 (EP), filed on Jun. 3, 2019.
Prior Publication US 2022/0306799 A1, Sep. 29, 2022
Int. Cl. C08G 63/08 (2006.01); C08G 63/78 (2006.01); C08G 63/91 (2006.01); C08K 5/37 (2006.01); C08K 5/372 (2006.01); C08L 67/04 (2006.01)
CPC C08G 63/08 (2013.01) [C08G 63/78 (2013.01); C08K 5/3725 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A process for the preparation of a melt-stable composition comprising aliphatic polyester by ring-opening polymerization of cyclic ester monomers, the process comprising the steps of:
(a) providing cyclic ester monomers and polymerization catalyst to a reactor,
(b) melt polymerizing the cyclic ester monomers to form a melt composition comprising aliphatic polyester,
(c) stabilizing the melt composition obtained in step (b) against aliphatic polyester depolymerization by adding at least one stabilizing agent to said melt composition comprising aliphatic polyester thereby obtaining a melt-stable composition, and
(d) optionally removing at least a portion of the residual cyclic ester monomers;
wherein the stabilizing agent is a compound of formula (I)

OG Complex Work Unit Chemistry
wherein
R1 is hydrogen or C1-6alkyl;
R2 is selected from the group consisting of hydrogen, C1-6alkyl, HO—C(═O)—CH(NHR7)—(CH2)n—C(═O)—, and C1-6alkylcarbonyl;
R3 is selected from the group consisting of hydroxyl, C1-6alkoxy and —NH—(CH2)p—C(═O)—OH;
m is an integer comprising 0, 1 or 2;
n is an integer comprising 1 or 2;
p is an integer comprising 1 or 2;
each R4 is independently hydrogen or C1-6alkyl;
each R5 is independently hydrogen or C1-6alkyl;
R6 is hydrogen, or a group of formula

OG Complex Work Unit Chemistry
wherein * indicates the point of attachment to the S of formula (I), and
R7 is selected from the group consisting of hydrogen, C1-6alkyl, and C1-6alkylcarbonyl, and wherein said polymerization catalyst has formula M(Y)g, in which M is a metal selected from the group consisting of the elements of columns 3 to 12 of the periodic table of the elements, Al, Ga, In, TI, Ge, Sn, Pb, Sb, Ca, Mg and Bi; wherein Y is independently selected from the group consisting of linear or branched alkyl with 1 to 20 carbon atoms, aryl having from 6 to 30 carbon atoms, alkoxy having from 1 to 20 carbon atoms, aryloxy having from 6 to 30 carbon atoms, and other oxide, carboxylate, and halide groups as well as elements of group 15 and/or 16 of the periodic table; and q is an integer from 1 to 6.