US 12,071,509 B2
Process for the production of a terephthalate polyester from a monomer mixture comprising a diester
Olivier Thinon, Rueil-Malmaison (FR); and Thierry Gauthier, Rueil-Malmaison (FR)
Assigned to IFP ENERGIES NOUVELLES, Rueil-Malmaison (FR)
Appl. No. 17/427,121
Filed by IFP Energies Nouvelles, Rueil-Malmaison (FR)
PCT Filed Jan. 27, 2020, PCT No. PCT/EP2020/051845
§ 371(c)(1), (2) Date Jul. 30, 2021,
PCT Pub. No. WO2020/156966, PCT Pub. Date Aug. 6, 2020.
Claims priority of application No. 1901023 (FR), filed on Feb. 1, 2019.
Prior Publication US 2022/0135735 A1, May 5, 2022
Int. Cl. C08G 63/80 (2006.01); C08G 63/183 (2006.01); C08G 63/85 (2006.01); C08J 11/24 (2006.01)
CPC C08G 63/183 (2013.01) [C08G 63/80 (2013.01); C08G 63/85 (2013.01); C08J 11/24 (2013.01); C08J 2367/02 (2013.01)] 12 Claims
 
1. A process for producing a terephthalate polyester, comprising:
a) a stage for preparing an esterification feedstock comprising at least one mixing section that is fed with at least one terephthalic acid feedstock and one diester monomer feedstock, wherein the amounts of at least the terephthalic acid feedstock and the diester monomer feedstock, introduced into the mixing section in the mixture, are adjusted so that the ratio of the total number of moles of diol units of formula —[C(n+1)H(2n+2)O2]—, n being an integer greater than or equal to 1, introduced into the mixing section, with respect to the total number of moles of terephthalate units of formula —[CO—(C6H4)—CO]— introduced into the mixing section, is between 1.0 and 2.0, wherein the mixing section is operated at a temperature of between 25° C. and 250° C. and at a pressure of greater than or equal to 0.1 MPa,
b) a stage for esterifying the esterification feedstock resulting from stage a), in order to produce at least one reaction effluent and one aqueous effluent, wherein the esterification stage comprises at least one reaction section, operated at a temperature between 150° C. and 400° C., at a pressure between 0.05 and 1 MPa, and with a residence time between 1 and 10 h, and at least one separation section,
c) a stage of polycondensation of the reaction effluent obtained in stage b) in order to obtain at least the terephthalate polyester and a diol effluent, the stage comprising at least one reaction section comprising at least one reactor in which the polycondensation is carried out and which is operated at a temperature between 200° C. and 400° C., at a pressure between 0.0001 and 0.1 MPa, with a residence time between 0.1 and 5 h, the reaction section also comprising at least one withdrawal of a diol effluent, and
d) a stage for treating the diols, comprising a recovery section that is fed at least with all or part of the diol effluent resulting from stage c), in order to obtain a diol effluent to be treated, and a section for purifying the diol effluent to be treated, in order to obtain a purified diol stream.