A process for the production of a terephthalate polyester, containing a stage a) for preparing an esterification feedstock containing at least one mixing section fed with at least one terephthalic acid feedstock and one diester monomer feedstock, where the ratio of the total number of moles of diol units with respect to the total number of moles of terephthalate units introduced into the mixing section is between 1.0 and 2.0, the mixing section being operated at a temperature between 25° C. and 250° C. and at a pressure greater than or equal to 0.1 MPa, an esterification stage b) to produce at least one reaction effluent and one aqueous effluent, a polycondensation stage c) to obtain at least the terephthalate polyester and an effluent containing at least one diol monomer, and a stage d) of treatment of the diols to obtain a purified diol stream.

A method of manufacturing bulked continuous carpet filament from recycled polymer. In various embodiments, the method includes: (1) reducing recycled polymer material into polymer flakes; (2) cleansing the polymer flakes; (3) melting the flakes into a polymer melt; (4) removing water and contaminants from the polymer melt by dividing the polymer melt into a plurality of polymer streams and exposing those streams to pressures below 25 millibars or another predetermined pressure; (5) recombining the streams; and (6) using the resulting purified polymer to produce bulked continuous carpet filament.

A method for producing polyester resin containing an ethylene terephthalate structural unit of not less than 85 mol%, the method comprising: a melt-polymerization step of continuously performing melt-polymerization in two or more polymerization vessels by using an aluminium compound and a phosphorus compound as a polymerization catalyst; and a solid phase polymerization step of performing solid phase polymerization after the melt-polymerization step, wherein a polymerization in a final polymerization vessel of the melt-polymerization step satisfies a condition represented by the following formula: 410≤T*RT*(P/Al)≤580, wherein T represents a temperature (°C) in the final polymerization vessel, RT represents residence time (hour) in the final polymerization vessel, and P/Al represents a molar ratio of phosphorus element to aluminium element in the polyester resin.

A method for producing polyester resin containing an ethylene terephthalate structural unit of not less than 85 mol%, the method comprising: a melt-polymerization step of continuously performing melt-polymerization in two or more polymerization vessels by using an aluminium compound and a phosphorus compound as a polymerization catalyst; and a solid phase polymerization step of performing solid phase polymerization after the melt-polymerization step, wherein a polymerization in a final polymerization vessel of the melt-polymerization step satisfies a condition represented by the following formula: 410≤T*RT*(P/Al)≤580, wherein T represents a temperature (°C) in the final polymerization vessel, RT represents residence time (hour) in the final polymerization vessel, and P/Al represents a molar ratio of phosphorus element to aluminium element in the polyester resin.

The present disclosure relates to a polyester film and a preparation method of the same. Since the polyester film includes a resin layer formed from a mixture comprising a polyester resin, which includes a first diol moiety derived from isosorbide and a second diol moiety derived from cyclohexanedimethanol in a controlled ratio, and polyethylene terephthalate in a specific ratio, it is possible to exhibit improved heat resistance and adhesion with excellent light transmittance.

The present disclosure relates to a polyester film and a preparation method of the same. Since the polyester film includes a resin layer formed from a mixture comprising a polyester resin, which includes a first diol moiety derived from isosorbide and a second diol moiety derived from cyclohexanedimethanol in a controlled ratio, and polyethylene terephthalate in a specific ratio, it is possible to exhibit improved heat resistance and adhesion with excellent light transmittance.

A type of polyester yarn for an industrial sewing thread and preparing method thereof are provided. The preparing method is composed of a viscosity enhancing by a solid state polycondensation and a melt spinning for a modified polyester, and the modified polyester is a product of esterification and polycondensation of evenly mixed terephthalic acid, ethylene glycol, tert-butyl branched dicarboxylic acid, trimethylsilyl branched diol and a doped Sb.sub.2O.sub.3 powder, wherein the tert-butyl branched dicarboxylic acid is selected from the group consisting of 5-tert-butyl-1,3-benzoic acid, 2-tert-butyl-1,6-hexanedioic acid, 3-tert-butyl-1,6-hexanedioic acid and 2,5-di-tert-butyl-1,6-hexanedioic acid. Moreover, the modified polyester is dispersed with a doped ZrO.sub.2 powder. An obtained fiber has an intrinsic viscosity drop of 23-28% when stored at 25° C. and R.H. 65% for 60 months.

A type of polyester yarn for an industrial sewing thread and preparing method thereof are provided. The preparing method is composed of a viscosity enhancing by a solid state polycondensation and a melt spinning for a modified polyester, and the modified polyester is a product of esterification and polycondensation of evenly mixed terephthalic acid, ethylene glycol, tert-butyl branched dicarboxylic acid, trimethylsilyl branched diol and a doped Sb.sub.2O.sub.3 powder, wherein the tert-butyl branched dicarboxylic acid is selected from the group consisting of 5-tert-butyl-1,3-benzoic acid, 2-tert-butyl-1,6-hexanedioic acid, 3-tert-butyl-1,6-hexanedioic acid and 2,5-di-tert-butyl-1,6-hexanedioic acid. Moreover, the modified polyester is dispersed with a doped ZrO.sub.2 powder. An obtained fiber has an intrinsic viscosity drop of 23-28% when stored at 25° C. and R.H. 65% for 60 months.

Semicrystalline bifuran polyesters wherein the diacid and/or diol components include bifuran units such as those derived from 2,2′-bifuran-5,5′-dicarboxylic acid (BFA), dimethyl-2,2′-bifuran-5,5′-dicarboxylate (BFE), and/or bis(hydroxyethyl) bifuranoate (BHEB) Polyethylene-BFE (PEBF) having a high ΔH.sub.f and high T.sub.g determined by DSC on the second heating ramp is described. Polybutylene-BFE (PBBF), polyhexylene-BFE (PHBF), polypropylene-BFE (PPBF), etc., are also described. Method for making bifuran polyesters includes melt esterification or transesterification and polycondensation of one or more monomers comprising a diacid component and a diol component, wherein the one or more monomers include a bifuran monomer, such as BFA, BFE, BHEB or BFD. Also described is a method of forming a bifuran polyester prepolymer in the melt, pelletization, crystallization, and solid state polymerization.

Semicrystalline bifuran polyesters wherein the diacid and/or diol components include bifuran units such as those derived from 2,2′-bifuran-5,5′-dicarboxylic acid (BFA), dimethyl-2,2′-bifuran-5,5′-dicarboxylate (BFE), and/or bis(hydroxyethyl) bifuranoate (BHEB) Polyethylene-BFE (PEBF) having a high ΔH.sub.f and high T.sub.g determined by DSC on the second heating ramp is described. Polybutylene-BFE (PBBF), polyhexylene-BFE (PHBF), polypropylene-BFE (PPBF), etc., are also described. Method for making bifuran polyesters includes melt esterification or transesterification and polycondensation of one or more monomers comprising a diacid component and a diol component, wherein the one or more monomers include a bifuran monomer, such as BFA, BFE, BHEB or BFD. Also described is a method of forming a bifuran polyester prepolymer in the melt, pelletization, crystallization, and solid state polymerization.