A method for preparing a polycarbonate ester includes feeding a monomer mixture containing (i) at least one compound selected from the group consisting of compounds of the following Formulae 1 and 3; (ii) a compound of the following Formula 2; and (iii) a 1,4:3,6-dianhydrohexitol to a polycondensation reactor and allowing the monomers and the 1,4:3,6-dianhydrohexitol to react to prepare the polycarbontate ester. The prepared polycarbonate ester has improved mechanical properties including tensile strength and impact strength: ##STR00001##

An amorphous polyester or copolyester composition comprises the reaction product of a crystalline or semicrystalline polyester or copolyester, optionally derived from a recycled waste stream, at least one diol or aromatic diacid or an ester of a diacid or a hydroxycarboxylic acid or a lactone or a dianhydride, and a catalyst, wherein the amorphous composition has a weight average molecular weight of at least 10,000 g/mol (polystyrene equivalent molecular weight) as measured by gel permeation chromatography.

The present disclosure relates to a method for continuously manufacturing an ester-based composition and a manufacturing system therefor, the method improving a manufacturing yield by optimizing process variables of each reactor of a reaction unit in which a plurality of reactors are connected in series.

The present disclosure relates to a catalyst system to produce crystallizable polyester compositions which comprise residues of terephthalic acid, neopentyl glycol (NRG), 1,4-cyclohexanedimethanol (CHDM), ethylene glycol (EG), and diethylene glycol (DEG), in certain compositional ranges having certain advantages and improved properties including recyclability. The present disclosure also relates to a catalyst system to produce crystallizable polyester compositions which comprise residues of recycled terephthalic acid, recycled neopentyl glycol (NRG), recycled 1,4-cyclohexanedimethanol (CHDM), recycled ethylene glycol (EG), and/or recycled diethylene glycol (DEG), in certain compositional ranges having certain advantages and improved properties including recyclability.

A process for producing a polyester composition from recycled polyesters.

A method for forming additive-containing reclaimed polyester can include: providing a feed of recycled polyester; providing a feed of polyester precursors; depolymerizing the recycled polyester to obtain depolymerized polyester monomers; polymerizing the depolymerized polyester monomers with the polyester precursors to form a reclaimed polyester; adding additives to the reclaimed properties to adjust for example, the color and/or viscosity, and providing the additive-containing reclaimed polyester as output.

A method for producing a polycondensate melt from a primary material and a secondary material from materials of substantially the same type is provided. A first partial melt stream of the primary material and a second partial melt stream of the secondary material are provided, and a measured value of the intrinsic viscosity of both partial melt streams is determined, and a difference value is calculated from the measured values. Based on the difference value, the intrinsic viscosity of the second partial melt stream is increased, reduced or maintained unchangedly by using a first melt treatment device. Subsequently, the two partial melt streams are combined into a common melt stream.

The present invention relates to a copolymerized polyester resin which can give film characteristics being suitable for a use as a heat-shrinkable label and which is excellent in the recycling property. According to the present invention, there is provided a copolymerized polyester resin which contains dicarboxylic acid and diol as constituting components, wherein the copolymerized polyester resin contains terephthalic acid as a main component of a dicarboxylic acid component, and contains ethylene glycol as a main component of a diol component, wherein a content of neopentyl glycol is from 18 to 32% by mole and a content of diethylene glycol is from 7 to 15% by mole when a total amount of the whole diol component is taken as 100% by mole, and wherein a molar proportion of each phosphorus compound contained in the copolymerized polyester resin and having a specific structure satisfies the specific inequality (1).

The aim of the present invention is to provide a copolymerized polyester resin for solving the problem of die staining and foreign matter adhesion to the film etc. in the continuous production of the film etc.; and the problem of recycling property of the copolymerized polyester. This copolymerized polyester resin contains dicarboxylic acid and did as constituting components, wherein the copolymerized polyester resin contains terephthalic acid as a main component of a dicarboxylic acid component, and contains ethylene glycol as a main component of a diol component, wherein a content of diethylene glycol is from 7 to 30% by mole and a content of triethylene glycol is from 0.05 to 2% by mole when a total amount of the whole diol component is taken as 100% by mole, wherein a content of a cyclic dimer consisting of terephthalic acid and diethylene glycol is 7000 ppm or less, and wherein a content of a cyclic dimer consisting of terephthalic acid, diethylene glycol and triethylene glycol is 200 ppm or less.

A polymer resin includes a copolymer of polyethylene terephthalate (PET). In the process of preparing PET, part of ethylene glycol is replaced with other components to obtain the copolymer of PET.