Sequential process for preparing polyester carbonates containing 1, 4: 3, 6-dianhydrohexitol

Abstract

The present invention relates to a process for preparing a polyester carbonate comprising at least one 1, 4: 3, 6-dianhydrohexitol by melt transesterification reaction wherein the process comprises reactions in a specific chronological order. The obtained polyestercarbonate has good color and high molecular weight. Furthermore, the present invention relates to a polyester carbonate obtained by said method and to a molded body comprising the polyester carbonate.

Description

[0001] This invention relates to a method for preparing a polyester carbonate comprising at least one 1,4:3,6-didehydrohexitol via a melt transesterification reaction, wherein the method comprises a reaction in a specific time sequence. The resulting polyester carbonate exhibits good color and high molecular weight. Furthermore, this invention relates to the polyester carbonate obtained by said method and molded articles comprising said polyester carbonate.

[0002] Polyesters, polycarbonates, and polycarbonates are known to possess good mechanical, heat-deformation, and weather-resistant properties. Depending on the monomers used, each polymer type exhibits some key characteristics characteristic of the material. For example, polycarbonates have particularly excellent mechanical properties, while polyesters generally demonstrate better chemical resistance. Depending on the monomers selected, polyester carbonates possess the performance characteristics of both of these polymer types.

[0003] Aromatic polycarbonates or polyesters, in particular, have weaknesses in terms of aging resistance and weather resistance. For example, absorbing ultraviolet light can cause these thermoplastic materials to yellow and sometimes become brittle. Aliphatic polycarbonates and polyester carbonates have better performance in these aspects, especially better aging resistance and / or weather resistance, as well as better optical properties (e.g., higher transmittance).

[0004] A common disadvantage of aliphatic polycarbonates or polyester carbonates is their low glass transition temperature. This low glass transition temperature reduces application possibilities and means that aliphatic polycarbonates or polyester carbonates are generally not considered equivalent alternatives to traditional aromatic polycarbonates or polyester carbonates.

[0005] Furthermore, the production methods of aliphatic polycarbonates, polyesters, and polyester carbonates face different challenges compared to corresponding methods involving aromatic reactants or products. For example, polyesters formed from cyclohexane-1,4-diethanol and cyclohexane-1,4-dicarboxylic acid are prepared from the dimethyl ester of this diacid. However, in transesterification reactions, phenyl esters are significantly more reactive than their aliphatic analogs. EP 3026074 A1 and EP 3248999 A1 describe methods for producing polyester carbonates using phenyl esters as an intermediate step. However, the production of these phenyl esters begins with the corresponding acyl chlorides. The production of acyl chlorides uses phosgene. Phosgene methods also require the use of solvents, typically halogenated solvents, which require laborious recovery or disposal. Therefore, it is advantageous to provide methods that do not use phosgene and ideally do not require solvents. Furthermore, additional process steps are required to purify or separate intermediates, making the described methods ecologically and economically expensive.

[0006] WO2020 / 126806 A1 describes a method for producing polyester carbonates without the use of phosgene and solvents. The advantage of this method is that it provides the desired high molecular weight polyester carbonate, as obtaining high molecular weight aliphatic polyesters or polyester carbonates via melt reaction has always been a challenge in the prior art. The method is also advantageous in terms of ease of installation and low cost in post-processing steps, as there is no need for laborious separation and purification of intermediates. However, this method requires a certain concentration of a highly efficient catalyst, such as 4-dimethylaminopyridine, to obtain a sufficiently high molecular weight (see the comparative examples of the invention). However, at higher concentrations, such catalysts can be corrosive, so it is advantageous to reduce the concentration of such catalysts. Reducing the amount of catalyst used is also advantageous for cost reasons. Higher catalyst concentrations can also result in a poorer color of the final product (see examples of the invention). If catalyst residues remain in the final product, this can also make the product difficult to further process and cause molecular weight loss, for example, during injection molding. Another disadvantage of the one-pot method described herein is the inability to control the polymer structure. When all reaction partners are pre-loaded in a one-pot method by definition, only polymers with random structures can be obtained. Depending on the reactivity of the monomers, it is possible that more reactive monomers will preferentially form blocks, while less reactive monomers will be incorporated later. Precise incorporation cannot be controlled in a one-pot process.

[0007] WO2021 / 122509 A1 describes a method for producing polyester carbonates, wherein a diester is first prepared from a linear or alicyclic dicarboxylic acid and a carbonate. A catalyst concentration of 0.005 to 0.02 wt% based on the components used in the method steps is disclosed. The diester is separated and purified from the mixture of the first method step. A dihydroxy compound, such as 1,4:3,6-didehydrohexitol and diaryl carbonate, is then added, and a subsequent reaction is carried out to produce the polymer. This method is sometimes referred to hereinafter as a two-step method. The diester separation step must always be performed in this document, which increases costs and therefore presents both ecological and economic disadvantages.

[0008] Based on existing technology, the object of the present invention is to solve the problems described in the prior art. In particular, the object of the present invention is to provide a method for preparing polyester carbonates via a melt transesterification reaction, a method that is particularly simple and simultaneously provides high-quality and high-performance polyester carbonates. The method should be as ecologically and economically advantageous as possible. This preferably means that the method comprises as few process steps as possible. In particular, the cost of the synthetic apparatus and / or the cost of post-processing of intermediates and / or the final product should be kept as low as possible. Furthermore, it is preferred to simultaneously obtain polyester carbonates with good color and / or sufficiently high molecular weight. Here, "sufficiently high molecular weight" is preferably understood to mean a polymer with a relative solution viscosity greater than 1.20, more preferably 1.21 to 1.65, more preferably 1.22 to 1.63, more preferably 1.23 to 1.62, and most preferably 1.26 to 1.55. The method should also preferably be able to form polyester carbonates in a targeted and controlled manner.

[0009] This invention achieves at least one, preferably all, of the above-described objectives. Surprisingly, the method flow of this invention reduces the number of process steps while yielding high-quality polyester carbonates with excellent performance. This provides a surprisingly economically and ecologically advantageous method. Particularly advantageous is the preparation of the diester in the first process step, at least partially. However, this diester does not require further purification; instead, the mixture optionally obtained through a sometimes incomplete reaction can be directly reacted subsequently. This is surprising because prior art indicates that the diester must be purified to obtain polyester carbonates with good color. 1,4:3,6-didehydrohexitol, along with optionally diaryl carbonate, is added only in the second step. It has been found that despite insufficient diester separation, side reactions do not adversely affect the quality and / or increase in molecular weight of the polymer. Therefore, the method of this invention is simpler and eliminates the need for additional equipment costs (tanks, pipelines, evaporators, etc.) for diester separation. This makes the method of this invention economically advantageous. However, it was also found that by separating the reaction in step (i) of the method of the present invention from the reaction in step (iii) of the method of the present invention, particularly by adding 1,4:3,6-didehydrohexitol later, the color of the polymer can be improved. Surprisingly, the concentration of the catalyst in step (i) of the method of the present invention can be reduced. This brings economic and ecological advantages. Despite the reduced catalyst concentration, the reaction in step (i) remains fast enough, preferably even faster than the conventional one-pot process (where at least 1,4:3,6-didehydrohexitol is still present in step (i)). The short reaction time has advantages, particularly in terms of energy used, yield per unit time (economic advantages), and reduced by-products and / or decomposition products, and also allows for efficient and continuous reaction. In summary, the method flow of the present invention provides a method that, while using a low catalyst concentration, also provides polyester carbonates with similarly good color (preferably improved compared to the prior art) and similarly good molecular weight (preferably higher than the prior art). The lower catalyst concentration also brings ecological and economic advantages (see above). A pleasant color in polyester carbonate indicates a low concentration of byproducts and / or decomposition products. These byproducts and / or decomposition products can also reduce, for example, the thermal stability or mechanical properties of the polymer. Therefore, the polyester carbonate provided by the method of the present invention has thermal stability or mechanical properties similar to (preferably improved) those of the prior art.

[0010] This invention is particularly advantageous in that it allows for the targeted construction of polymer structures. On one hand, the method of this invention allows for the sequential addition of catalysts in different process steps. This enables the catalyst to be selectively present only in the process steps where one or more catalysts are to function. It is also highly advantageous that certain monomers (regardless of their reactivity) react first and are incorporated into the polyester carbonate as block or pre-reacted products (e.g., trimers). Therefore, the polymer structure can be better controlled. This can lead to targeted performance improvements. For example, specific monomers with sensitive end groups can react first in step (ii) of the method of this invention to protect them from heat and oxidation. The method of this invention also allows only certain monomers to be bridged via ester groups, while other monomers are optionally, preferably, bridged via carbonate units. This can also benefit the performance characteristics of the resulting polyester carbonate. For example, if certain ester groups are prone to hydrolysis, it is reasonable to limit the proportion of these ester groups in the resulting polyester carbonate. Therefore, it is advantageous to be able to control the polymer structure during the process of this invention. Furthermore, it has been found that since the reaction is carried out under vacuum in at least some process steps, the vapor typically contains a mixture of substances composed of different components. This typically includes a mixture of condensation products, reactants, various catalysts, and byproducts. The present invention simplifies the separation of these vapor mixtures because the different process steps produce more defined vapors. This makes vapor separation generally easier.

[0011] According to the present invention, a method for preparing polyester carbonate via a melt transesterification reaction is provided, comprising the following steps in sequence: (i) Condensing at least one dicarboxylic acid, preferably at least one aliphatic dicarboxylic acid, with at least one diaryl carbonate in the presence of at least one catalyst, wherein chemical compounds eliminated during the condensation process are removed to provide mixture (I). Optional method step (ii), which includes (ii) Contacting at least one diol with the mixture (I) obtained directly from step (i) of method, and at least partially condensing the compounds present in step (ii), wherein chemical compounds eliminated during the condensation process are removed, to provide mixture (II). (iii) Contacting at least one 1,4:3,6-disodehydrated hexitol and optionally a further diaryl carbonate with a mixture (I) obtained directly from method step (i), or contacting with a mixture (II) obtained directly from method step (ii) when performing method step (ii), and performing condensation, wherein the chemical compounds eliminated in the reaction are removed.

[0012] The present invention also provides a method for preparing polyester carbonates via a melt transesterification reaction, comprising the following steps in sequence: (i) Condensing at least one dicarboxylic acid, preferably at least one aliphatic dicarboxylic acid, with at least one diaryl carbonate in the presence of at least one catalyst, wherein chemical compounds eliminated during the condensation process are removed to provide mixture (I). Optional method step (ii), which includes (ii) Adding at least one diol to the mixture (I) obtained directly from step (i), and at least partially condensing the compounds present in step (ii), wherein chemical compounds eliminated during the condensation process are removed, to provide mixture (II). (iii) Add at least one 1,4:3,6-disodehydrated hexitol and optionally a further diaryl carbonate to the mixture (I) obtained directly from method step (i), or to the mixture (II) obtained directly from method step (ii) when performing method step (ii), and perform condensation, wherein the chemical compounds eliminated in the reaction are removed.

[0013] The process of molten transesterification is well known to those skilled in the art. For example, see Schnell, “Chemistry and Physics of Polycarbonates”, Polymer Reviews, Vol. 9, Interscience Publishers, New York, London, Sydney 1964. In molten transesterification, the starting material undergoes transesterification in the melt with the aid of a suitable catalyst and optional other additives. Clearly, the temperature depends on the melting point of the starting material.

[0014] The term "contact" is used in this invention. This term should cover embodiments of adding a component / mixture, etc., to another component / mixture, etc., and vice versa. Those skilled in the art know how to achieve such contact between components and / or mixtures. For example, this can be done by adding components and / or mixtures, preloading components and / or mixtures, mixing components and / or mixtures, dripping components and / or mixtures, etc. Those skilled in the art will understand that the term "addition" as sometimes used in this invention can be understood as synonymous with "contact." Those skilled in the art will also understand that the term "addition" as sometimes used in this invention can be included in the term "contact" or represent a subordinate form of "contact."

[0015] Those skilled in the art are also familiar with the term "condensation" or "condensation". "Condensation" is preferably understood as a reaction in which two molecules (of the same or different substances) combine to form a larger molecule, wherein a molecule of a chemically simple substance is eliminated. The compound eliminated during condensation is removed in method step (i) or also in method steps (ii) and / or (iii).

[0016] According to the present invention, in method step (i), at least one dicarboxylic acid and at least one diaryl carbonate ester undergo condensation in the presence of at least one catalyst. The dicarboxylic acid here is preferably an aliphatic dicarboxylic acid.

[0017] Preferably, the at least one dicarboxylic acid is selected from compounds of formulas (1), (2), and (3), furanyl dicarboxylic acid, naphthalene dicarboxylic acid, phthalic acid, isophthalic acid, and terephthalic acid, wherein (1) (2) In equations (1) and (2), B is independently a CH2 group or a heteroatom selected from O and S, preferably a CH2 group or an oxygen atom. R1 is each independently a single bond or an alkylene group having 1 to 10 carbon atoms, preferably a single bond or an alkylene group having 1 to 5 carbon atoms, especially a single bond; and n is a value from 0 to 3, preferably 0 or 1, and (3) In equation (3), each R 2 Each of the above is an aliphatic group having 16 to 44 carbon atoms, which optionally contains one or more double bonds.

[0018] Preferably, the at least one dicarboxylic acid is an aliphatic dicarboxylic acid, therefore furanyl dicarboxylic acid, naphthalene dicarboxylic acid, phthalic acid, isophthalic acid, and terephthalic acid need to be removed from the above group. More preferably, the at least one dicarboxylic acid is a mixture of at least one aliphatic dicarboxylic acid (preferably selected from the above dicarboxylic acids) and at least one aromatic dicarboxylic acid (preferably selected from furanyl dicarboxylic acid, naphthalene dicarboxylic acid, phthalic acid, isophthalic acid, and terephthalic acid). Most preferably, it is a combination of cyclohexane-1,4-dicarboxylic acid and terephthalic acid. Also particularly preferred is a combination of dimer fatty acid and terephthalic acid.

[0019] In addition, other dicarboxylic acids may be optionally added, such as tetradihydrofuran-2,5-dicarboxylic acid, tetradihydrodimethylfuran-2,5-dicarboxylic acid, decahydronaphthalene-2,4-dicarboxylic acid, decahydronaphthalene-2,5-dicarboxylic acid, decahydronaphthalene-2,6-dicarboxylic acid, decahydronaphthalene-2,7-dicarboxylic acid, furanyldicarboxylic acid, naphthalenedicarboxylic acid, phthalic acid, isophthalic acid, and terephthalic acid. Any desired mixture may also be used. In addition to alicyclic acids, small amounts of other aliphatic acids may be used, such as those selected from 2,2,4-trimethyladipic acid, 2,4,4-trimethyladipic acid, 2,2,5-trimethyladipic acid, and 3,3-dimethylglutaric acid.

[0020] Regarding equations (1) and (2), it should be understood that when R1 represents a single bond, R1 correspondingly contains zero carbon atoms.

[0021] Particularly preferred is that the dicarboxylic acid of formula (1) or (2) is selected from cyclohexane-1,4-dicarboxylic acid, cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,2-dicarboxylic acid, tetradihydrofuran-2,5-dicarboxylic acid, tetradihydrodimethylfuran-2,5-dicarboxylic acid, decahydronaphthalene-2,4-dicarboxylic acid, decahydronaphthalene-2,5-dicarboxylic acid, decahydronaphthalene-2,6-dicarboxylic acid, and decahydronaphthalene-2,7-dicarboxylic acid. Any desired mixture may also be used. Most preferably is cyclohexane-1,4-dicarboxylic acid, cyclohexane-1,3-dicarboxylic acid, or cyclohexane-1,2-dicarboxylic acid.

[0022] Particularly preferably, each R in equation (3) 2 Each group is an aliphatic group having 17 to 44 carbon atoms, particularly preferably 18 to 44 carbon atoms, particularly preferably 19 to 44 carbon atoms, particularly preferably 20 to 44 carbon atoms, particularly preferably 21 to 44 carbon atoms, particularly preferably 22 to 43 carbon atoms, particularly preferably 23 to 42 carbon atoms, particularly preferably 24 to 41 carbon atoms, particularly preferably 25 to 40 carbon atoms, particularly preferably 26 to 39 carbon atoms, particularly preferably 27 to 38 carbon atoms, particularly preferably 28 to 37 carbon atoms, particularly preferably 29 to 37 carbon atoms, particularly preferably 30 to 37 carbon atoms, particularly preferably 31 to 37 carbon atoms, particularly preferably 32 to 37 carbon atoms, and most particularly preferably 33 to 37 carbon atoms.

[0023] In this invention, unless otherwise defined, the term "aliphatic" or "aliphatic group" refers to a hydrocarbon group that does not contain an aromatic unit. However, the group may have one or more double bonds. Furthermore, the group may have one or more rings. These rings may be fused together (e.g., one or more carbon atoms may belong to two rings) or linked together by, for example, alkylene or alkylidene groups. The one or more rings may have one or more double bonds. However, it should be noted that, according to this invention, aromatic rings are not included in the definition of "aliphatic." Furthermore, the one or more rings or the aliphatic group itself may be interrupted by one or more heteroatoms. However, this is less preferred.

[0024] In this invention, unless otherwise stated, the term "alkyl" or "alkyl group" preferably refers to an alkane structure with one hydrogen atom removed. The alkyl group according to the invention can be straight-chain or branched. It is saturated, therefore there are only single bonds between adjacent carbon atoms. Preferably, the alkyl group includes methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, neopentyl, 1-ethylpropyl, n-hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1,2-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethyl-1-methylpropyl, 1-ethyl-2-methylpropyl, 1-ethyl-2-methylpropyl, etc. The choice of these structures may be limited if the definition of the number of carbon atoms differs within the context of this invention.

[0025] In this invention, unless otherwise stated, the term "alkylene" or "alkylene group" preferably refers to a bridged alkane structure in which two hydrogen atoms are removed from different carbon atoms. In this context, the two hydrogen atoms removed from the two carbon atoms can be removed from any carbon atom in the alkane structure. This means that the two carbon atoms can be adjacent, but not necessarily adjacent. The alkylene can be straight-chain or branched. It is saturated. If the alkylene has only one carbon atom, it is a methylene (-CH2-) that is connected to the rest of the molecule by two single bonds. Preferably, the alkylene group comprises methylene, ethylene, n-propylene, isopropylene, n-butylene, sec-butylene, tert-butylene, n-pentylene, 1-methylbutylene, 2-methylbutylene, 3-methylbutylene, neopentylene, 1-ethylpropylene, n-hexylene, 1,1-dimethylpropylene, 1,2-dimethylpropylene, 1,2-dimethylpropylene, 1-methylpentylene, 2-methylpentylene, 3-methylpentylene, 4-methyl Examples of alkylene compounds include pentylene, 1,1-dimethylbutylene, 1,2-dimethylbutylene, 1,3-dimethylbutylene, 2,2-dimethylbutylene, 2,3-dimethylbutylene, 3,3-dimethylbutylene, 1-ethylbutylene, 2-ethylbutylene, 1,1,2-trimethylpropylene, 1,2,2-trimethylpropylene, 1-ethyl-1-methylpropylene, 1-ethyl-2-methylpropylene, and 1-ethyl-2-methylpropylene. The choice of these structures may be limited if the definition of the number of carbon atoms differs in this invention. Furthermore, according to this invention, the alkylene group may optionally have at least one carbonyl group, optionally at least one halogen atom, and / or optionally be interrupted by at least one heteroatom. Examples of such alkylene groups include -C(=O)-(CH2)4-C(=O)-, -C(=O)-(CH2)3-C(=O)-, -C(=O)-(CH2)2-C(=O)-, -C(CF3)2, -O-(CH2)4-O-, -O-(CH2)3-O-, -O-(CH2)2-O-, etc. However, according to the invention, the above structures are less preferred. Furthermore, the invention also refers to "cycloalkylene groups". In this case, the above description applies, but additionally, the group may additionally have one or more rings. These rings may be fused together (i.e., one or more carbon atoms may belong to two rings, for example), or linked together by, for example, alkylene groups. The one or more rings may have one or more double bonds. Furthermore, these one or more rings or aliphatic groups themselves may be interrupted by one or more heteroatoms. However, this is less preferred.

[0026] In this invention, unless otherwise stated, the term "alkylidene" or "alkylidene group" preferably refers to a bridged alkane structure in which two hydrogen atoms are removed from the same carbon atom. The alkylidene group optionally has at least one carbon-carbon double bond, optionally at least one carbonyl group, and / or optionally at least one halogen atom. Preferably, the alkylidene group includes isopropylidene, n-propylidene, isoheptidene, etc.

[0027] In this invention, unless otherwise stated, the term "aryl" preferably refers, in each case, independently to a straight-chain, cyclic, or branched alkyl group that is mono-, di-, or poly-substituted with an aryl group. In this invention, unless otherwise stated, the term "aryl" preferably refers to an aromatic hydrocarbon group. Examples of "aryl" include phenyl, o-tolyl, p-tolyl, m-tolyl, naphthyl, phenanthryl, or anthracene.

[0028] In this invention, unless otherwise stated, the term "alkoxy group" preferably refers to a straight-chain, cyclic, or branched alkyl group connected to an oxygen atom by a single bond (-OR). Alkoxy groups according to the invention preferably have 1 to 6 carbon atoms. Particularly preferred, the alkoxy group includes methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentoxy, 1-methylbutoxy, 2-methylbutoxy, 3-methylbutoxy, neopentoxy, 1-ethylpropoxy, cyclohexyloxy, cyclopentoxy, n-hexyloxy, 1,1-dimethylpropoxy, 1,2-dimethylpropoxy, 1,2-dimethylpropoxy, 1-methylpentoxy, 2-methylpentoxy, 3-methylpentoxy, 4-methylpentoxy, 1,1-dimethylbutoxy, 1,2-dimethylbutoxy, 1,3-dimethylbutoxy, 2,2-dimethylbutoxy, 2,3-dimethylbutoxy, 3,3-dimethylbutoxy, 1-ethylbutoxy, 2-ethylbutoxy, 1,1,2-trimethylpropoxy, 1,2,2-trimethylpropoxy, 1-ethyl-1-methylpropoxy, 1-ethyl-2-methylpropoxy, or 1-ethyl-2-methylpropoxy. The choice of these structures may be limited if the definition of the number of carbon atoms differs in this invention.

[0029] Based on the above definitions, those skilled in the art will understand other definitions not explicitly mentioned above.

[0030] According to a preferred embodiment of the present invention, R in formula (3) 2 It is represented by the following formula (R2A): (R2A) Wherein Y is a bridging structure selected from alkylene groups having 1 to 4 carbon atoms, alkylidene groups having 1 to 4 carbon atoms, and cycloalkylene groups having 4 to 12 carbon atoms, preferably 4 to 10 carbon atoms, wherein the cycloalkylene group optionally contains one or more double bonds and / or optionally is fused to one or more other cycloalkylene groups, wherein the one or more other cycloalkylene groups optionally each have one or more double bonds. R, which is adjacent to the bridging structure 11 The group is attached to any position in the bridging structure, and Each R 11 Each is independently an alkylene group having 1 to 12 carbon atoms or an alkylidene group having 1 to 12 carbon atoms, wherein the structure of formula (R2A) contains 16 to 44 carbon atoms, and wherein the positions marked with "~" in formula (R2A) are the positions of the (C=O) groups shown in formula (3).

[0031] Particularly preferably, formula (R2A) is represented by one of formulas (R2Aa), (R2Ab), (R2Ac), or (R2Ad), wherein (R2Aa), (R2Ab), (R2Ac) and (R2Ad), Each R 11 The definition of each "~" is the same as in (R2A), the rings in formula (R2Ac) are optionally equipped with one or two double bonds, and each ring in formula (R2Ad) is optionally equipped with one or two double bonds independently of each other. Furthermore, it is particularly preferred that R in formula (3) 2 It is represented by a mixture of at least two different formulas (R2Aa), (R2Ab), (R2Ac), and (R2Ad). This also includes mixtures of different groups belonging to the same formula (e.g., two groups belonging to formula (R2Aa)).

[0032] As mentioned above, the rings of formula (R2Ac) and / or (R2Ad) can each contain one or two double bonds. This typically does not include the formation of aromatic rings. As explained further below, when R in formula (3) 2 When a mixture contains at least two different formulas (R2Aa), (R2Ab), (R2Ac), and (R2Ad), it may also contain a small proportion of an aromatic bridging structure Y of formula (R2A). However, this is less preferred.

[0033] Particularly preferred, each R in formula (R2A) and / or formula (R2Aa), (R2Ab), (R2Ac) or (R2Ad) 11Each is an alkylene group having 1 to 10 carbon atoms, provided that the structure of formula (R2A) and / or formula (R2Aa), (R2Ab), (R2Ac) or (R2Ad) contains 16 to 44 carbon atoms.

[0034] Similarly, preferably, in equation (3) R 2 The groups described by (R2A), (R2Aa), (R2Ab), (R2Ac) and / or (R2Ad) have 21 to 44 carbon atoms. Also preferably, the groups in formula (3) consisting of R... 2 The groups described by (R2A), (R2Aa), (R2Ab), (R2Ac), and / or (R2Ad) have 17 to 44 carbon atoms, more preferably 18 to 44 carbon atoms, more preferably 19 to 44 carbon atoms, more preferably 20 to 44 carbon atoms, more preferably 21 to 44 carbon atoms, more preferably 22 to 43 carbon atoms, more preferably 23 to 42 carbon atoms, more preferably 24 to 41 carbon atoms, more preferably 25 to 40 carbon atoms, more preferably 26 to 39 carbon atoms, more preferably 27 to 38 carbon atoms, more preferably 28 to 37 carbon atoms, more preferably 29 to 37 carbon atoms, more preferably 30 to 37 carbon atoms, more preferably 31 to 37 carbon atoms, more preferably 32 to 37 carbon atoms, and very particularly preferably 33 to 37 carbon atoms. Those skilled in the art can apply the aforementioned limited number of carbon atoms to the specifications regarding the number of carbon atoms.

[0035] Especially preferred are the different R values ​​in formulas (R2A) and / or (R2Aa), (R2Ab), (R2Ac), or (R2Ad). 11 They have different numbers of carbon atoms.

[0036] Very particularly preferred, formula (3) is a dimer fatty acid. Those skilled in the art know that dimer fatty acids are mixtures of various fatty acids. Their main structures are shown below: Fully hydrogenated compounds are preferred here. Dimeric fatty acids are typically mixtures. They are formed by the condensation of various unsaturated fatty acids. For this purpose, fatty acids containing conjugated double bonds (conjugated acids) react with (one or more) other unsaturated fatty acids. Conjugated linoleic acid is particularly preferred for this purpose. This reaction is usually carried out via a Diels-Alder addition reaction, thereby generating a partially unsaturated C6 ring. Thus, the dimer fatty acid initially contains at least partially one or more double bonds. In addition to the dimer, the mixture of dimer fatty acids may also contain trimers and monomers of fatty acids. Oleic acid and linoleic acid are particularly preferred to be reacted. The double bonds contained in the dimer fatty acid are usually hydrogenated.

[0037] Very particularly preferred, formula (3) is a dimer fatty acid with 36 carbon atoms.

[0038] Dimeric fatty acids are commercially available, for example, under the trade names Pripol 1009, Pripol 1006, Pripol 1025, Radicacid 0960, Radicacid 0975, Radicacid 0976, Radicacid 0977, Radicacid 0978, and Unidyme 18. As described above, Pripol and its derivatives are obtained through the oligomerization reaction of unsaturated fatty acids, preferably C18 acids. The dimerization reaction yields a mixture of monocarboxylic acids, dicarboxylic acids, and tricarboxylic acids. The monofunctional compounds are usually separated by distillation. At this point, a mixture of 80% difunctional compounds and 20% trifunctional compounds is typically obtained, which is further purified by distillation to enrich the difunctional compounds. The saturated compounds are obtained by hydrogenation. Pripol, as a dimer fatty acid, is a purified mixture mainly containing C36 diacids.

[0039] Furthermore, preferably, the diaryl carbonate in method step (i) (and / or the optional further diaryl carbonate in method step (ii)) is selected from compounds of formula (5). (5) R, R', and R'' can be independently the same or different from each other, and are hydrogen, optionally branched C1-C 34 Alkyl, C7-C 34 Alkyl aryl, C6-C 34 Aryl, nitro, carbonyl-containing, carboxyl-containing, or halogen-containing groups. In this case, the diaryl carbonate in step (i) and the optional diaryl carbonate in step (iii) may be the same or different, preferably the same.

[0040] Particularly preferred is that the at least one diaryl carbonate is diphenyl carbonate, 4-tert-butylphenyl ester carbonate, di(4-tert-butylphenyl) carbonate, biphenyl-4-ylphenyl carbonate, di(biphenyl-4-yl) carbonate, 4-(1-methyl-1-phenylethyl)phenyl ester carbonate, di[4-(1-methyl-1-phenylethyl)phenyl] carbonate, bis(methyl salicylate), bis(ethyl salicylate), bis(propyl salicylate), bis(2-benzoylphenyl), bis(phenyl salicylate), and / or bis(benzyl salicylate). Particularly preferably, the at least one diaryl carbonate is diphenyl carbonate, 4-tert-butylphenyl phenyl carbonate, di(4-tert-butylphenyl) carbonate, biphenyl-4-ylphenyl carbonate, di(biphenyl-4-yl) carbonate, 4-(1-methyl-1-phenylethyl)phenylphenyl carbonate, and / or di[4-(1-methyl-1-phenylethyl)phenyl] carbonate. Particularly preferably, the at least one diaryl carbonate is diphenyl carbonate.

[0041] Furthermore, according to the present invention, at least one catalyst is present in at least step (i). Preferably, this is an inorganic base and / or an organic catalyst. Particularly preferably, the at least one catalyst is pK. B Inorganic or organic bases with a value of 5 or higher.

[0042] Preferably, the at least one inorganic base or the at least one organic catalyst is selected from: hydroxides, carbonates, halides, phenolates, diphenolates, fluorides, acetates, phosphates, hydrogen phosphates, and borates of lithium, sodium, potassium, cesium, calcium, barium, and magnesium; tetramethylammonium hydroxide; tetramethylammonium acetate; tetramethylammonium fluoride; tetramethylammonium tetraphenylborate; tetraphenylphosphonium fluoride; tetraphenylphosphonium tetraphenylborate; dimethyldiphenylammonium hydroxide; tetraethylammonium hydroxide; hexadecyltrimethylammonium tetraphenylborate; hexadecyltrimethylammonium phenolate; diazabicycloundecene (DBU); and diazabicyclononene (DBU). BN), 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-phenyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7,7'-hexylidene di-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7,7'-decylidene di-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7,7'-dodecylidene di-1,5,7-triazabicyclo[4.4.0]dec-5-ene, phosphazene base P1-t-Oct (tert-octyliminotris(dimethylamino)phosphine), phosphazene base P1-t-Butyl (tert-butyliminotris(dimethylamino)phosphine), and 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diaza-2-phosphine (BEMP). Any desired mixture may also be used.

[0043] Preferably, the catalyst used in step (i) is selected from alkylamines, imidazoles (derived from), guanidine-derived bases, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, hexamethylphosphorimide triamide, 1,2-dimethyl-1,4,5,6-tetrahydropyridine, 7- Methyl-1,5,7-triazabicyclodec-5-ene, ethylimidazolium, N,N-diisopropylethylamine (Hünig base), pyridine, 1,1,3,3-tetramethylguanidine (TMG), 4-dimethylaminopyridine and its derivatives, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), and mixtures thereof.

[0044] Particularly preferably, the at least one catalyst in step (i) is an organic base, preferably the aforementioned organic bases, especially alkylamines, imidazoles (derived from), guanidine bases such as triazabicyclodecene, DMAP and corresponding derivatives, DBN and DBU, with DMAP being the most preferred. A particular advantage of these catalysts is that, in step (iii) of the invention, they can be separated from the chemical compounds eliminated in the condensation reaction, for example, by vacuum. However, preferably, the catalyst is retained in mixture (I). According to the invention, it has been found that the catalyst concentration can be kept very low, particularly compared to conventional two-step and / or one-pot processes of the prior art. Therefore, the catalyst concentration in mixture (I) can be particularly low compared to conventional one-pot and / or two-step processes (where mixture (I) is not produced in a one-pot process because all the units constituting the subsequent polymer are present from the beginning; this means that similar mixtures always contain components different from those in mixture (I); in a two-step process, the diester is separated from mixture (I)).

[0045] However, it is also possible that the catalyst has been at least partially removed from the mixture of method step (i) along with the chemical compounds eliminated during the condensation process in method step (i). This means that the catalyst may optionally be only partially contained in mixture (I) (relative to the amount used in method step (i)) or may not be contained in mixture (I) at all. However, as stated above, the at least one catalyst used in method step (i) is preferably at least partially contained in mixture (I).

[0046] In step (i), the at least one catalyst is used, preferably in an amount of 1 to 1000 ppm, more preferably 2 to 500 ppm, more preferably 5 to 50 ppm, and most preferably 10 to 30 ppm, based on the sum of the weights of the dicarboxylic acid and the diaryl carbonate. When multiple dicarboxylic acids are present, this refers to all present dicarboxylic acids. The same applies to the diaryl carbonate. Unless otherwise stated, ppb and ppm in this invention are understood to refer to parts by weight.

[0047] In another embodiment, the method of the present invention is characterized in that: the reaction in step (i) is carried out in the presence of at least one first catalyst and optionally a second catalyst; the condensation reaction in step (iii) is carried out at least in the presence of the second catalyst, and optionally in the presence of the first catalyst. Preferably, the first catalyst is at least one tertiary nitrogen base. Catalysts described in detail above are particularly preferred. The second catalyst is preferably at least one basic alkali metal salt or alkaline earth metal salt and / or phosphonium or ammonium catalyst. Here, the proportion of alkali metal cations or alkaline earth metal cations in step (iii) is preferably 0.00001 to 0.0050% by weight, based on all components used in steps (i) to (iii).

[0048] Also preferably, the second catalyst is at least one phosphonium or ammonium catalyst. Very particularly preferably, the second catalyst is a mixture of an alkaline alkali metal salt or alkaline earth metal salt with a phosphonium or ammonium catalyst. Particularly suitable are phosphonium catalysts of formula (K1) or ammonium catalysts of formula (K2): (K1), (K2) Ra, Rb, Rc, and Rd can each be the same or different C1-C10 alkyl, C6-C14 aryl, C7-C15 aralkyl, or C5-C6 cycloalkyl, preferably methyl or C6-C14 aryl, especially methyl or phenyl, and X- can be anion, such as hydroxide, sulfate, borate, especially tetraphenylborate, hydrogen sulfate, bicarbonate, carbonate, acetate, or halide ion, preferably chloride, borate, or acetate, or alkoxy or aryloxy of formula -OR, wherein R can be C6-C14 aryl, C7-C15 aralkyl, or C5-C6 cycloalkyl, preferably phenyl.

[0049] Particularly preferred catalysts are tetraphenylphosphonium chloride, tetrabutylphosphonium acetate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium hydroxide, and tetraphenylphosphonium phenolate, with tetraphenylphosphonium phenolate being particularly preferred. Tetrabutylphosphonium acetate is also preferred.

[0050] Other particularly preferred catalysts are tetramethylammonium hydroxide, tetramethylammonium acetate, tetramethylammonium fluoride, tetramethylammonium tetraphenylborate, dimethyl diphenylammonium hydroxide, tetraethylammonium hydroxide, hexadecyltrimethylammonium tetraphenylborate, and hexadecyltrimethylammonium phenolate.

[0051] As described above, it is also preferred that the second catalyst is an alkaline alkali metal salt or alkaline earth metal salt. Particularly preferred is that the second catalyst is selected from inorganic or organic alkali metal salts and inorganic or organic alkaline earth metal salts. Furthermore, it is preferred that the alkali metal cation included in step (iii) is lithium ion, potassium ion, sodium ion, cesium ion, or a mixture thereof.

[0052] The second catalyst used is an organic or inorganic alkali metal or alkaline earth metal salt, preferably a weak acid (pKa of 3 to 7 at 25°C) of organic or inorganic alkali metal or alkaline earth metal salt. Suitable weak acids are, for example, carboxylic acids, preferably C2-C22 carboxylic acids, such as acetic acid, propionic acid, oleic acid, stearic acid, lauric acid, benzoic acid, 4-methoxybenzoic acid, 3-methylbenzoic acid, 4-tert-butylbenzoic acid, p-tolueneacetic acid, 4-hydroxybenzoic acid, salicylic acid, partial esters of polycarboxylic acids, such as monoesters of succinic acid, and branched aliphatic carboxylic acids, such as 2,2-dimethylpropionic acid, 2,2-dimethylpropionic acid, 2,2-dimethylbutyric acid, and 2-ethylhexanoic acid. However, strong acids, such as organic or inorganic alkali metal or alkaline earth metal salts of hydrochloric acid, can also be used.

[0053] Suitable organic and inorganic salts are or derived from sodium bicarbonate, potassium bicarbonate, lithium bicarbonate, sodium carbonate, lithium carbonate, potassium carbonate, sodium acetate, potassium acetate, lithium acetate, sodium stearate, potassium stearate, lithium stearate, sodium oleate, lithium oleate, potassium oleate, sodium benzoate, potassium benzoate, lithium benzoate, disodium salts, dipotassium salts, and dilithium salts of BPA. Calcium bicarbonate, barium bicarbonate, magnesium bicarbonate, strontium bicarbonate, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, and the corresponding oleates can also be used. Corresponding phenolic salts, especially phenolic salts, can also be used. These salts can be used alone or in combination.

[0054] The second catalyst is preferably selected from sodium hydroxide, lithium hydroxide, sodium phenoxide, lithium phenoxide, sodium benzoate, lithium benzoate, lithium chloride, lithium acetylacetonate, and cesium carbonate, as well as mixtures of these substances. Sodium phenoxide, lithium phenoxide, sodium hydroxide, lithium hydroxide, sodium benzoate, lithium benzoate, lithium chloride, and / or lithium acetylacetonate are particularly preferred. Lithium chloride is preferably used in aqueous solution form, for example, a 15% solution.

[0055] These catalysts are preferably 10 based on 1 mole of the component used in step (iii) of method. -2 Up to 10 -8 mol, preferably 10 -2 Up to 10 -6 The amount used is in molar amounts. The amount of alkaline alkali metal salt or alkaline earth metal salt can be from 0.01 to 20 ppm, preferably from 0.05 to 15 ppm, and particularly preferably from 0.1 to 10 ppm.

[0056] Therefore, in this embodiment, a first catalyst and an optional second catalyst are present in method step (i). Preferably, both the first and second catalysts are present in method step (i). It is not absolutely necessary for both catalysts to be catalytically active for the reaction carried out in method step (i). It is also possible that the second catalyst is primarily needed or exerts its catalytic effect only in method step (iii). Nevertheless, it may still be present in method step (i).

[0057] Furthermore, preferably, at least one first catalyst is present in method step (i), at least one second catalyst is optionally added in method step (ii), and at least one second catalyst is present in method step (iii). Clearly, the at least one first catalyst is different from the at least one second catalyst. Similarly, it is clear that when the at least one second catalyst is added in method step (ii), the at least one second catalyst is present in method step (iii). Alternatively, when method step (ii) is not performed, the at least one second catalyst is added in method step (iii). Therefore, it is also present in method step (iii). It is also preferred that if method step (ii) is performed, the at least one first catalyst is also present in method step (ii), and / or the at least one first catalyst is also present in method step (iii). Here, it is not necessarily required that the at least one first catalyst be catalytically active for the reaction carried out in the optional method steps (ii) and / or method steps (iii).

[0058] In step (i) of the method of the present invention, gas generation is observed. This gas generation is due to the formation and subsequent release of carbon dioxide. This carbon dioxide is a chemical compound eliminated during the condensation process of step (i). The carbon dioxide can be removed under standard pressure or by applying a vacuum. Preferably, the temperature of step (i) is initially increased. More preferably, the temperature of step (i) is increased to 150°C to 200°C. It is also preferable to gradually increase the temperature to 215°C to 250°C, more preferably 215°C to 240°C. This can further improve the condensation conversion rate.

[0059] Particularly preferred is that the condensation reaction in method step (i) is completed at least 70%, more preferably at least 80%, more preferably at least 90%, and particularly preferably at least 95%, before starting method step (ii) or, if there is no method step (ii), before starting method step (iii). From an economic point of view, it is reasonable to achieve the highest possible conversion rate before starting the next method step. It may also be advantageous to have started method step (ii) or (iii) at a slightly earlier stage. The conversion rate can be determined by methods known to those skilled in the art. For example, the reaction conversion rate can be inferred from the amount of carbon dioxide generated. The amount of carbon dioxide generated can advantageously be measured using, for example, a mass flow meter.

[0060] Alternatively, the conversion rate can be determined by measuring the concentration of the carboxylic acid groups present. Preferably, before starting method step (ii), or before starting method step (iii) in the absence of method step (ii), at most 30%, more preferably at most 20%, more preferably at most 10%, and particularly more preferably at most 5% of the dicarboxylic acid initially used in method step (i) is still present.

[0061] However, according to the invention, this also means that it is not necessary to completely react all the present dicarboxylic acids with the stoichiometric diaryl carbonate before initiating method step (ii) or (iii). However, according to the invention, it is preferable to carry out method step (i) for such a long time that observable gas release substantially ceases before initiating method step (ii) or (iii).

[0062] According to the present invention, it has been found that the reaction time required to achieve the desired conversion rate, preferably the conversion rate, in step (i) of the condensation reaction can be shortened by the method of the present invention. Here, the shortening is preferably based on a comparison with conventional one-pot reaction schemes, in which all structural units constituting the subsequent polymer (particularly 1,4:3,6-disodehydrated hexitol) are present in the conventional one-pot process. It has also been found that the catalyst concentration in step (i) of the present invention can be reduced compared to prior art two-step methods. Here, it is preferred to achieve the same, and particularly preferred, better polymer properties (particularly color and / or molecular weight). Furthermore, the method of the present invention offers the advantage of fewer reaction steps (eliminating the need for separation and / or purification of mixture (I), thus making the method of the present invention more ecologically and economically advantageous overall.

[0063] Method step (i) provides a mixture (I). This mixture (I) comprises the reaction product of the at least one dicarboxylic acid and the at least one diaryl carbonate. The reaction product may be a diaryl ester of the dicarboxylic acid. Depending on the conversion rate of the condensation reaction in method step (i), mixture (I) may contain at least partially still free dicarboxylic acid and / or dicarboxylic acid monoaryl esters. Furthermore, the catalyst used in method step (i) may remain wholly or partially contained in mixture (I). The catalyst may also be removed by the temperature used in method step (i) and / or by the escaping gas. In this case, the catalyst is not present in mixture (I). However, in method step (i), compounds (excluding carbon dioxide) that escape due to the temperature used may also be condensed again and then optionally supplied back to the mixture and / or mixture (I) of method step (i). Especially when diphenyl carbonate is used as a diaryl carbonate, a corresponding evaporation occurs in method step (i). Therefore, it is advantageous from an ecological and / or economic point of view to supply the evaporated starting material back to method step (i). Furthermore, in method step (i), the chemical compounds eliminated during the condensation process are removed. This removal can be complete, substantially complete, or only partially performed. Those skilled in the art will recognize that removing these eliminated chemical compounds affects the equilibrium of the chemical reaction in method step (i). Therefore, they are able to select the optimal operating procedure for the appropriate method scheme. Sometimes, the method scheme of method step (i) can be automatically accompanied by the removal of the chemical compounds eliminated during the condensation process through, for example, temperature control, gas generation, and / or the application of a vacuum.

[0064] Particularly preferred is that, in step (i) of the method of the present invention, 2.01 to 2.5 moles, more preferably 2.05 to 2.2 moles, of diaryl carbonate are used per mole of the at least one dicarboxylic acid, and further diaryl carbonate is added in step (iii). Therefore, a slight stoichiometric excess relative to the dicarboxylic acid is preferably used in step (i). Alternatively, all the diaryl carbonate required for the reaction (i.e., required for steps (i) and (iii)) may have already been added in step (i). However, in this case, side reactions, such as increased Frisch rearrangement, may occur.

[0065] Preferably, the total ratio of diaryl carbonate to the amount of the dicarboxylic acid (one or more) and the amount of the diol (including 1,4:3,6-didehydrohexitol) used is about 0.98 to 1.02:1.02 to 0.98. It will be apparent to those skilled in the art that the amount of diaryl carbonate used in step (i) is optional and also depends on the amount of dicarboxylic acid subsequently incorporated into the polyester carbonate via a condensation reaction. This is especially true when further diaryl carbonate is added in step (iii).

[0066] Furthermore, the method step (i) of the present invention preferably includes at least one of the steps (ia) to (ic), and particularly preferably all of them: (ia) Melting all components present in step (i), namely at least the at least one dicarboxylic acid and the at least one diaryl carbonate, in the presence of at least one catalyst. Preferably, this is carried out under an inert gas atmosphere, preferably under nitrogen and / or argon. Step (ia) is preferably carried out under solvent-free conditions. The term "solvent" is known to those skilled in the art. According to the invention, the term "solvent" is preferably understood to be a compound that does not participate in the chemical reaction in any of steps (i), (ii), and / or (iii). An exception is the compound formed by the reaction (e.g., phenol when diphenyl carbonate is used as the at least one diaryl carbonate). Of course, trace amounts of solvent in the starting compound cannot be excluded. The invention should preferably cover this situation. However, according to the invention, active steps involving the addition of such solvents are preferably avoided; (ib) Heat the mixture, preferably the melt obtained in step (ia). Steps (ia) and (ib) may overlap, as heating may also be required in step (ia) to produce a melt. Heating is preferably initially carried out to 150°C to 180°C; (ic) The mixture, preferably the mixture obtained in step (ib), is reacted, wherein mixing energy is introduced, preferably by stirring. Step (ic) may also overlap with step (ib), since heating can already initiate the reaction of the mixture. The melt has preferably been heated to a temperature of 150 to 180°C at standard pressure in step (ib). Depending on the catalyst selected, the temperature may be maintained at 160 to 200°C. Alternatively, the temperature in step (ic) may be gradually increased to 200 to 300°C, preferably 210 to 260°C, more preferably 215 to 240°C, depending on the observed reactivity. Reactivity can be estimated by gas generation using methods well known to those skilled in the art. In principle, this step may also be performed at higher temperatures, but at higher temperatures, side reactions (e.g., discoloration) may occur. Therefore, higher temperatures are less preferred. Preferably, method step (ic) is carried out at standard pressure. Stirring is performed until gas generation substantially ceases. The reaction time of this method step can be adjusted by temperature control. According to the present invention, under these conditions, the aromatic alcohols (e.g., phenol when using diphenyl carbonate) generated by the reaction of the at least one carboxylic acid with the at least one diaryl carbonate may be partially removed together (see above).

[0067] The reaction time of step (ic) depends on the amount of feedstock, the temperature profile used, and optional stirring conditions (gas exchange and / or surface exchange). Preferably, the reaction time of step (ic) is 0.5 hours to 24 hours, more preferably 0.75 hours to 5 hours, and particularly preferably 1 hour to 3 hours. Such a reaction time is preferred here so that gas generation essentially stops / the reaction is essentially complete or the desired conversion rate is achieved (see above).

[0068] Method step (i) can be performed in batches or continuously. It may be advantageous to perform method step (i) in batches for reaction time reasons. Therefore, it is preferred that method step (i) be performed in batches. All reactors familiar to those skilled in the art can be used for this purpose. If the method is performed continuously, method step (i) can be carried out, for example, in a tubular reactor. If the method is performed in batches, the use of a stirred tank is particularly considered. No significant increase in viscosity has been observed in method step (i) and / or mixture (I), therefore a stirrer familiar to those skilled in the art can be used. Furthermore, it is preferable to install a reflux tower on such a stirred tank to condense the optionally evaporated starting material and / or reaction products and supply them again to method step (i) (see above).

[0069] According to the invention, step (i) is preferably carried out in the absence of 1,4:3,6-didehydrhexitol. Particularly preferably, all the 1,4:3,6-didehydrhexitol required for the construction of the polyester carbonate is added only in step (iii). Preferably, mixture (I) does not contain 1,4:3,6-didehydrhexitol and / or the reaction products of 1,4:3,6-didehydrhexitol.

[0070] Surprisingly, according to the present invention, the mixture (I) of method step (i) can be used in method step (ii) or (iii) without further purification. In this regard, the statement "mixture (I) or (II) obtained directly from method step (i) or (ii)" implies, in particular, that the desired target product is not purified and / or separated. Specifically, with respect to method step (i), this means that although the generated diaryl dicarboxylic acid ester is present in mixture (I), it is not separated from it. Preferably, mixture (I) contains at least a first catalyst in addition to the generated diaryl ester.

[0071] The method of the present invention optionally includes a method step (ii), which (if present) is performed after method step (i) and before method step (iii). In method step (ii), at least one diol is contacted with the mixture (I) obtained directly from step (i); or in method step (ii), at least one diol is added to the mixture (I) obtained directly from step (i), and the compound present in method step (ii) is at least partially condensed, wherein chemical compounds eliminated during the condensation process are removed to provide mixture (II). The purpose of method step (ii) is particularly to condense said at least one diol with the compound in mixture (I), especially with the diaryl dicarboxylic acid ester in mixture (I).

[0072] According to a preferred embodiment of the invention, in the case of method step (ii), the mixture (I) no longer contains diaryl carbonate or aromatic alcohol generated by method step (i). However, method step (ii) may also be carried out in the presence of diaryl carbonate and / or aromatic alcohol remaining from method step (i). Particularly preferably, the at least one catalyst remaining from method step (i) is still present in method step (ii).

[0073] Preferably, the diol in step (ii) is aliphatic or alicyclic.

[0074] Particularly preferably, the diol in step (ii) is selected from cyclohexane-1,2-diol, cyclohexane-1,3-diol, cyclohexane-1,4-diol, cyclohexane-1,2-diethanol, cyclohexane-1,3-diethanol, cyclohexane-1,4-diethanol, 2,2-bis(4-hydroxycyclohexyl)propane, tetrahydrofuran-2,5-diethanol, 2,2,4,4-tetramethylcyclobutane-1,3-diol, cyclobutane-1,1-diyldiethanol, [8-(hydroxymethyl)-3-tricyclo[ 5.2.1.02,6]decyl]methanol, 2-butyl-2-ethylpropane-1,3-diol, 2-(2-hydroxyethoxy)ethanol, 2,2,4-trimethylpentane-1,3-diol, 2,2-dimethylpropane-1,3-diol, propane-1,2-diol, propane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, octane-1,8-diol, 1,4:3,6-dihydrohexitol and compounds of formula (4), (4) Where each r and each s are independent numbers from 0 to 4, and each R 3 Each of them has an independent structure consisting of (R3A), (R3B), (R3C), and (R3D). (R3A) Where a is 0 or 1, (R3B) Where b is 0 or 1, (R3C) (R3D) The positions marked with "~" in equations (R3A) to (R3D) are (CH2) as shown in equation (4). r Group or (CH2) s The position of the group. Preferably, the diol in step (ii) is not 1,4:3,6-didehydrohexitol. Furthermore, preferably, the diol in step (ii) is a diol containing a primary alcohol group. Particularly preferably, the diol in step (ii) is one of the aforementioned diols containing a primary alcohol group. Therefore, 2,2,4,4-tetramethylcyclobutane-1,3-diol and 1,4:3,6-didehydrohexitol should be removed from the above list.

[0075] Preferably, in equation (4), each r and each s is a number from 0 to 2, very particularly preferably 0 or 1, and each R 1 The structures are independent of each other and are of formula (R1A). Particularly preferably, r and s in formula (4) are 1, and R... 1 The structure is of formula (R1A). Very particularly preferred, formula (4) is TCD-diethanol (also known as TCD alcohol, tricyclic decanediethanol, or [8-(hydroxymethyl)-3-tricyclic[5.2.1.02,6]decyl]ethanol). TCD-diethanol usually exists as a mixture of isomers. Up to 32 isomers can exist. Depending on the polymerization conditions, the initial number and / or type of isomers in the monomer may vary in the resulting polymer.

[0076] Furthermore, the present invention does not exclude the presence of aromatic diols in method step (ii). However, these are preferred only in low proportions. Particularly preferred is that, based on the total molar amount of diol compounds used, method step (ii) contains an additional 20 mol%, more preferably 10 mol%, and very particularly preferably 5 mol% of aromatic diol compounds. In these cases, according to the present invention, it is preferred to still refer to aliphatic polyester carbonate. However, it is particularly preferred that aromatic diol compounds are not used in method step (ii). Generally, aromatic compounds in polyester carbonate reduce its UV stability and weather resistance. This is particularly disadvantageous for outdoor applications. In addition, the aromatic portion in polyester carbonate reduces the surface hardness of the molded articles made therefrom, which optionally leads to the need for coating.

[0077] These additional aromatic diol compounds are preferably selected from bisphenol A, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-dihydroxybiphenyl (DOD), 4,4'-dihydroxydiphenyl ether (DOD ether), bisphenol B, bisphenol M, and bisphenol (I) to (III). In these formulas (I) to (III), R' is each a C1-C4 alkyl, aralkyl, or aryl, preferably methyl or phenyl, and very particularly preferably methyl.

[0078] Preferably, at least one further (second) catalyst is added in method step (ii). This (second) catalyst has been described in more detail above.

[0079] Preferably, the chemical compounds (one or more) eliminated in at least a portion of the condensation reaction in step (ii) are removed by vacuum. Therefore, it is preferred that the method of the present invention is characterized in that volatile components with boiling points lower than the diesters, glycols, and / or compounds formed in step (ii) are separated during the condensation process in step (ii), wherein the pressure is optionally gradually reduced. When different volatile components are separated, gradual separation is preferred. Gradual separation is also preferred to ensure that the one or more volatile components are separated as completely as possible. Volatile components refer to one or more chemical compounds eliminated during the condensation process. Phenol is preferred.

[0080] Gradually reducing the pressure can be done, for example, by reducing the pressure once the top temperature drops, to ensure continuous removal of the chemical compounds eliminated during the condensation process.

[0081] In step (ii), the separation of the condensation product is preferably carried out at a temperature of 180°C to 320°C, more preferably 190°C to 280°C, more preferably 195°C to 260°C, and even more preferably 200°C to 250°C. Furthermore, it is preferable that the vacuum during the separation process is from 500 mbar to 0.01 mbar. Particularly preferred is separation by gradually decreasing the vacuum. Very particularly preferred is that the vacuum in the final stage is from 10 mbar to 0.01 mbar.

[0082] Polyester carbonates with targeted structures can be constructed via method step (ii). Surprisingly, although the construction can proceed sequentially and therefore sequentially, there is no need to separate or isolate the individual intermediates. Those skilled in the art will understand that the diester formed in method step (i) undergoes transesterification with the diol in optional method step (ii). This can result in the formation of a low-polyester block. The molecular weight of this low-polyester block can be influenced by temperature control and / or vacuum control. Preferably, the low-polyester block is a trimer formed from the at least one diol linked to the at least one dicarboxylic acid via an ester group, wherein the other end of the dicarboxylic acid is also linked to the at least one diol via an ester group. Similarly, trimers can be formed, for example, comprising a centrally aligned diol linked to two dicarboxylic acids via two ester groups (wherein the terminal groups of these two dicarboxylic acids are typically esterified with aryl groups). This structural unit is highly reactive due to the presence of terminal aryl groups. This trimer can be considered the simplest low-polyester structural unit. In step (iii) of the method, the structural unit can then be condensed with 1,4:3,6-disodehydrated hexitol and diaryl carbonate to generate the desired polyester carbonate.

[0083] Such low polyester structural units are particularly preferably incorporated into polyester carbonates via acid groups or aryl ester groups, rather than via alcohol OH groups. However, those skilled in the art will know that due to preparation, terminal OH groups may also be present in small amounts.

[0084] The low-polyester is particularly preferably a trimer formed from cyclohexane-1,4-diethanol and cyclohexane-1,4-dicarboxylic acid, or from cyclohexane-1,4-diethanol, cyclohexane-1,4-dicarboxylic acid, and terephthalic acid. The low-polyester is also preferably a trimer formed from TCD-diethanol and dimer fatty acids, or from TCD-diethanol, dimer fatty acids, and terephthalic acid.

[0085] The advantage of this method lies particularly in its ability to offset and / or circumvent differences in the reactivity of different monomers. Furthermore, it is advantageous that, in the resulting polyester carbonate, the diol is selectively formed into an ester group relative to the carbonate group of the same diol. This can significantly affect the resulting properties of the polyester carbonate. Another advantage is that this method allows for the formation of ester groups with primary alcohols. Such ester groups have been found to be particularly stable in principle during step (iii), especially compared to ester groups formed from diols containing secondary alcohol groups. Exceptions are secondary alcohols that cannot undergo elimination, such as tetramethylcyclobutanediol. Therefore, by selectively constructing the polyester carbonate in this way, bonds stable to transesterification reactions can be introduced, which can have a positive impact on performance.

[0086] Preferably, step (ii) is carried out in the same reactor as step (i). Since the viscosity is not expected to increase significantly in step (ii), this reactor is suitable for carrying out step (ii) in the same way. Obviously, step (ii) can also be carried out in a reactor where step (iii) is carried out later. Similarly, step (ii) can certainly be carried out in a separate reactor where only step (ii) is carried out.

[0087] The method of the present invention further includes step (iii), wherein at least one 1,4:3,6-disodehydrated hexitol and optionally a further diaryl carbonate are added to the mixture (I) obtained directly from step (i), or, if step (ii) has been performed, to the mixture (II) obtained directly from step (ii), and a condensation reaction is carried out, wherein the chemical compounds eliminated in the reaction are removed. In this case, step (iii) is preferably carried out in the presence of a catalyst, particularly preferably at least one second catalyst. As described above, according to the present invention, a first catalyst present in step (i) and a second catalyst optionally added to step (ii) and present in or added to step (iii) are distinguished. For this purpose, the at least one second catalyst mentioned above is referred to herein.

[0088] Particularly preferred is that, in step (iii), in addition to at least one 1,4:3,6-disodehydrated hexitol, another diol is contacted or added. Preferably, the method of the present invention is characterized in that, in step (iii), at least one other diol is additionally contacted with the mixture (I) obtained directly from step (i), or, if step (ii) has been performed, with the mixture (II) obtained directly from step (ii). Also preferably, the method of the present invention is characterized in that, in step (iii), at least one other diol is additionally added to the mixture (I) obtained directly from step (i), or, if step (ii) has been performed, to the mixture (II) obtained directly from step (ii). This other diol is preferably the diol described with respect to step (ii). Very particularly preferred is that the at least one other diol is tricyclodecanediethanol (sometimes also called TCD-diethanol).

[0089] Also surprisingly, according to the present invention, the components of method step (iii) can be directly contacted or added to the mixture (I) or (II) obtained from the previously performed method steps without separation and / or purification of mixture (I) or (II). Those skilled in the art will recognize that byproducts and / or decomposition products formed prior to the point in time of method step (iii) can adversely affect the resulting polyester carbonate, particularly in terms of increased molecular weight and / or color. Because no further purification and / or separation method steps are required, the method of the present invention is particularly eco-friendly and economical.

[0090] According to the invention, at least one 1,4:3,6-didehydrohexitol is used in method step (iii). It is known to those skilled in the art that 1,4:3,6-didehydrohexitol is typically selected from isomannitol, isosorbide, and isosorbide. It can be a bio-based structural unit, thereby bringing with it all the advantages of bio-based monomers and the resulting polymers (e.g., better sustainability, as they are made from renewable raw materials). A particularly preferred feature of the method of the invention is that the at least one 1,4:3,6-didehydrohexitol is isosorbide. It is particularly advantageous that the at least one 1,4:3,6-didehydrohexitol is dried before being added to method step (iii). This drying can be performed using methods known to those skilled in the art. The dried 1,4:3,6-didehydrohexitol particularly helps to better control the process of method step (iii).

[0091] Similarly, in step (iii) of the method of the present invention, a further diaryl carbonate may optionally be contacted or supplied. This may be at least one diaryl carbonate. The diaryl carbonate optionally contacted or added in step (iii) may be the same as or different from the at least one diaryl carbonate contacted or added in step (i). Preferably, the diaryl carbonate optionally contacted or added in step (iii) is the same as the at least one diaryl carbonate contacted or added in step (i).

[0092] Contacting or adding a further diaryl carbonate in step (iii) can preferably be specifically used to reduce the OH end group content of the resulting polyester carbonate. For example, such an operation is described in JP2010077398 A.

[0093] The diaryl carbonate ester optionally contacted or added in step (iii) is preferably selected from compounds of formula (5), as described in more detail above. In particular, the preferred embodiments and combinations thereof described above also apply here. Especially preferably, the diaryl carbonate ester optionally contacted or added in step (iii) is diphenyl carbonate.

[0094] Preferably, in step (iii), 0.75 to 1.00 moles, more preferably 0.85 to 0.95 moles of diaryl carbonate are used for every 2 moles of the at least one 1,4:3,6-didehydrohexitol. If other diols are also used in step (iii), the moles of diaryl carbonate are based on the total moles of the OH functional compounds present (i.e., 1,4:3,6-didehydrohexitol plus the other diols). The amount of diaryl carbonate described in step (iii) is particularly preferred when 2.01 to 2.5 moles, more preferably 2.05 to 2.2 moles of diaryl carbonate are used for every 1 mole of the at least one dicarboxylic acid in step (i), and further diaryl carbonate is added in step (ii). This method is preferred compared to a method using all the diaryl carbonate required for the entire method of the present invention in step (i). Therefore, the loss of diaryl carbonate and the generation of byproducts in step (i) and optionally (ii) can be minimized.

[0095] As described above, the amount of diaryl carbonate used in step (iii) depends on the amount already used in step (i). This amount, in turn, depends on the ratio of ester groups (determined by using dicarboxylic acids) to carbonate groups (determined by using diols including 1,4:3,6-didehydrohexitol) present in the polyester carbonate to be produced. Preferably, in step (i) the diaryl carbonate is used at least twice the molar ratio of dicarboxylic acid, preferably 2.1 times; in step (iii), the remaining molar amount of diaryl carbonate is used minus the excess used in step (i), wherein the remaining molar amount of diaryl carbonate refers to the molar amount when the molar ratio of diaryl carbonate to the sum of dicarboxylic acid and 1,4:3,6-didehydrohexitol (and optionally other dicarboxylic acids and / or other diols) is 1:1, minus the molar amount of diaryl carbonate used in step (i). Those skilled in the art will understand that deviations from the above ratios are also possible. For example, by using a proportionally larger amount of diaryl carbonate, the molecular weight can be controlled, particularly limited, and / or the content of phenolic OH groups in the polymer can be reduced. Conversely, if the content of phenolic OH groups should be as high as possible, the proportion of diaryl carbonate can be reduced. It is also possible to proportionally remove (e.g., by applying vacuum reaction conditions) and / or decompose (e.g., by thermal decomposition) diols during the reaction. In this case, a proportionally smaller amount of diaryl carbonate can also be used. In method step (iii), a condensation reaction occurs in the mixture (I) obtained from method step (i) or the mixture (II) obtained from method step (ii), wherein at least the chemical compounds eliminated during the condensation process are removed. The condensation reaction in method step (iii) is preferably understood as a further condensation reaction. In this invention, a “further” condensation reaction means that a condensation reaction has at least partially occurred in method step (i). Preferably, this is the reaction of the at least one dicarboxylic acid with the at least one diaryl carbonate, wherein the aromatic alcohol is eliminated. However, a further condensation reaction may also have occurred until an oligomer is formed (see method step (ii)).

[0096] When only the at least one first catalyst is used in method step (i), the at least one second catalyst is added in method step (ii) and / or method step (iii).

[0097] In a preferred embodiment, the first catalyst and the second catalyst are present in method step (i).

[0098] Alternatively, a portion of the first catalyst and / or a portion of the second catalyst may be used in step (i), and then the remaining portions of each may be used in step (iii).

[0099] Preferably, in step (iii), the chemical compound(s) eliminated during the condensation process are removed by vacuum. Therefore, the method of the present invention is preferably characterized in that, in step (iii), the chemical compound(s) eliminated during the condensation process are separated by gradually decreasing pressure. Gradual separation is preferred when different volatile components are separated. Gradual separation is also preferred to ensure that the one or more volatile components are separated as completely as possible. These volatile components are one or more chemical compounds eliminated during the condensation process. This is particularly true of the generated aromatic alcohols, more preferably phenol.

[0100] The pressure can be gradually reduced, for example, as follows: reduce the pressure once the temperature at the top of the column drops to ensure continuous removal of the chemical compounds eliminated during the condensation process. When the pressure reaches 1 mbar, preferably <1 mbar, condensation continues until the desired viscosity is achieved. This can be achieved, for example, by monitoring the torque, i.e., stopping the polycondensation reaction when the desired stirrer torque is reached.

[0101] In step (iii), the separation of the condensation product is preferably carried out at a temperature of 180°C to 320°C, more preferably 190°C to 280°C, more preferably 195°C to 260°C, and even more preferably 200°C to 250°C. Furthermore, preferably, the vacuum during the separation process is 500 mbar to 0.01 mbar. Particularly preferably, the separation is carried out gradually by decreasing the vacuum. Very particularly preferably, the vacuum in the final stage is 10 mbar to 0.01 mbar.

[0102] Step (iii) can be performed in batches or continuously. Preferably, step (iii) is performed continuously. During step (iii), the viscosity increases. Above a certain viscosity / molecular weight, the condensation reaction in the stirred tank may become ineffective because surface renewal decreases and the removal of low molecular weight condensation products (especially phenol) becomes difficult. Therefore, it is particularly reasonable to carry out step (iii) in a process unit such as a high-viscosity reactor, a disc or grid reactor, an extruder, or a thin-film evaporator. However, step (iii) may also be carried out in a stirred tank, optionally in the same stirred tank as step (i), if the stirred tank has a suitable stirring device.

[0103] Surprisingly, another advantage of the method of the present invention is the improved utilization of reactor volume. In method step (i), a relatively large portion of the reactor volume is occupied by at least one diaryl carbonate. During method step (i), at least a portion of the diaryl carbonate is removed through a reaction that specifically generates carbon dioxide. Furthermore, the generated aromatic alcohols, preferably phenol, are also removed at least partially in method step (i). This means that at the end of method step (i), the reactor volume of method step (i) is reduced by about 50%. If a conventional one-pot process is used, this volume, which is not available for further condensation reactions to produce polyester carbonates, would actually be lost because it cannot be utilized (it is no longer filled by adding further substances, since all substances are already present in the reactor from the beginning). However, in the sequential operation mode according to the present invention, it is possible to add further reactants and further diaryl carbonates required for the reaction after the removal of carbon dioxide in the first stage. This makes more efficient use of the reactor volume, which improves the economic efficiency of the method. Therefore, it is preferred that the method of the present invention be carried out in a single reactor overall. This means that method step (i), optional method step (ii), and method step (iii) are carried out in a single reactor.

[0104] According to the present invention, a polyester carbonate is obtained after method step (iii). It may optionally undergo further purification steps, optional granulation steps, etc. Such steps are known to those skilled in the art.

[0105] Preferably, the relative solution viscosity of the polyester carbonate obtained according to the method of the present invention is greater than 1.20, more preferably 1.21 to 1.65, more preferably 1.22 to 1.63, more preferably 1.23 to 1.62, and very particularly preferably 1.26 to 1.55. According to the present invention, the relative solution viscosity (ηrel; also known as eta rel) is preferably determined at 25°C using an Ubbelohde viscometer in dichloromethane at a concentration of 5 g / L. Those skilled in the art are familiar with methods for determining relative solution viscosity using an Ubbelohde viscometer. According to the present invention, this is preferably performed according to DIN 51562-3; 1985-05. Here, the flow time of the polyester carbonate to be tested is measured by the Ubbelohde viscometer to subsequently determine the viscosity difference between the polymer solution and its solvent. For this purpose, the Ubbelohde viscometer is first calibrated using measurements of pure solvents dichloromethane, trichloroethylene, and tetrachloroethylene (always at least 3 measurements, up to 9 measurements are performed). A formal calibration is then performed using the solvent dichloromethane. The polymer sample was then weighed and dissolved in dichloromethane, and the flow time of this solution was measured three times. The average flow time was corrected using the Hagenbach correction method, and the relative solution viscosity was calculated.

[0106] This preferred relative solution viscosity ensures that the polyester carbonate obtained by the method of the present invention possesses sufficient mechanical properties. "Sufficient" here refers to its mechanical properties, particularly its ductility in unnotched impact tests at room temperature, which is comparable to that of conventional aromatic polycarbonates. This preferably means that the resulting polyester carbonate rods will not break in unnotched Charpy or Elliptic impact tests, or will only break at extremely high energy absorption levels—especially preferably exhibiting NB (no brake).

[0107] It will be apparent to those skilled in the art how the raw materials, particularly dicarboxylic acid, diaryl carbonate, and 1,4:3,6-didehydrohexitol (and optionally other diols), are used in steps (i) to (iii) to obtain the polyester carbonate of the desired composition. Particularly preferred in step (i) is the use of 8 mol% to 40 mol% of dicarboxylic acid, more preferably 15 mol% to 35 mol% of dicarboxylic acid, based on the total molar amount of dicarboxylic acid and 1,4:3,6-didehydrohexitol. Likewise, in step (iii) is preferred the use of 60 mol% to 92 mol% of 1,4:3,6-didehydrohexitol, more preferably 65 mol% to 85 mol% of 1,4:3,6-didehydrohexitol, based on the total molar amount of dicarboxylic acid and 1,4:3,6-didehydrohexitol.

[0108] Also preferably, in step (i) the use of 2 to 14 mol%, more preferably 3 to 12 mol%, particularly preferably 3.5 to 7.5 mol%, of at least one dicarboxylic acid, especially preferably a dimer fatty acid, based on the total molar amount of the dicarboxylic acid used, optionally other diols, and 1,4:3,6-didehydrohexitol. Also preferably, in step (ii) the use of 4 to 25 mol%, particularly preferably 5 to 20 mol%, also preferably 7 to 18 mol%, particularly preferably 10 to 15 mol%, very particularly preferably 5 to 10 mol%, or very particularly preferably 8 to 12 mol%, of at least one other diol, especially preferably TCD-diethanol, based on the total molar amount of the dicarboxylic acid used, optionally other diols, and 1,4:3,6-didehydrohexitol. Alternatively, in step (iii), at least 4 to 25 mol%, more preferably 5 to 20 mol%, also preferably 7 to 18 mol%, very particularly preferably 10 to 15 mol%, or very particularly preferably 8 to 12 mol%, of at least one other diol, particularly preferably TCD-diethanol, may be used, based on the total molar amount of the dicarboxylic acid, optional other diol, and 1,4:3,6-dadehydrohexitol used. Furthermore, at least 55 mol%, more preferably at least 65 mol%, also preferably at least 75 mol%, and very particularly preferably at least 80 mol%, of 1,4:3,6-dadehydrohexitol, particularly preferably isosorbide, is used, based on the total molar amount of the dicarboxylic acid, optional other diol, and 1,4:3,6-dadehydrohexitol used.

[0109] Also provided according to the invention is a polyester carbonate obtained by the method of the invention, optionally employing all preferred embodiments and / or combinations thereof, wherein the method must include method step (ii). As described above, the polyester carbonate has a specific structure and is therefore prepared sequentially. For example, the polyester carbonate comprises a specific targeted and controlled linkage of monomers via ester groups and a similarly targeted and controlled linkage via carbonate groups. Thus, the performance characteristics of the polyester carbonate according to the invention can be targeted. Particularly preferred is that at least 50 mol% of the polyester carbonate according to the invention and / or the polyester carbonate obtained by the method according to the invention, more preferably at least 70 mol%, and very particularly preferably at least 75 mol%, is bio-based. For the purposes of this invention, the term "bio-based" means that the relevant chemical compound was available and / or obtained from renewable and / or sustainable raw materials at the date of application, and / or preferably from such renewable and / or sustainable raw materials. Renewable and / or sustainable raw materials are preferably understood to be raw materials regenerated by natural processes at a rate commensurate with their degradation rate (see CEN / TS 16295:2012). This term is specifically used to distinguish raw materials produced from fossil raw materials (also known as petroleum-based). Whether a raw material is bio-based or petroleum-based can be determined by measuring the carbon isotopes in the raw material, since fossil raw materials contain C... 14 The relative amount is low. For example, this can be done according to ASTM D6866-18 (2018) or ISO 16620-1 to -5 (2015) or DIN SPEC 91236 2011-07. According to the invention, the term "bio-based" is preferably used for those having a concentration greater than 0.1 × 10⁻⁶. -12 More preferably greater than 0.2×10 -12 A very special preference is given to values ​​greater than 0.3 × 10⁻⁶. -12 C 14 Compounds with high carbon isotope content. In particular, isosorbide and dimer fatty acids are bio-based.

[0110] Another aspect of the invention provides molded articles comprising the polyester carbonate of the invention. The molded articles of the invention can be prepared, for example, by injection molding, extrusion, and blow molding. Another processing method is to produce the molded articles by deep drawing from pre-prepared sheets or films. Example

[0111] Materials used: Cyclohexanedicarboxylic acid: Cyclohexane-1,4-dicarboxylic acid; CAS 1076-97-7, 99%; Tokyo Chemical Industries, Japan, abbreviated as CHDA. Elemental analysis shows that the sodium content in CHDA is less than 1 ppm. Diphenyl carbonate: Diphenyl carbonate, 99.5%, CAS 102-09-0; Acros Organics (DPC), Belgium. 4-Dimethylaminopyridine: 4-Dimethylaminopyridine; ≥ 98.0%; pure; CAS 1122-58-3; Sigma-Aldrich, Munich, Germany, abbreviated as DMAP Isosorbide: Isosorbide (CAS: 652-67-5), 99.8%, Polysorb PS A; Roquette Frères (62136, Leytrem, France); abbreviated as ISB Lithium hydroxide monohydrate (CAS: 1310-66-3); purity >99.0%; Sigma-Aldrich Cyclohexane-1,4-diethanol: CAS: 105-08-8, Aldrich 99% (a mixture of cis / trans isomers; abbreviated as CHDM) Terephthalic acid (CAS 100-21-0): 99+%, Acros Organics, Belgium Isophthalic acid: (CAS: 121-91-5), 99%, Alfa Aesar, ThermoFisher (Kandel) GmbH, (76870, Kandel, Germany) Tricyclodecanediethanol (CAS: 26896-48-0); mixture of isomers; OQ Chemicals, 40789 Montheim, Germany (abbreviated as TCD-diethanol) Dimeric fatty acid: Pripol 1009 (CAS: 68783-41-5); Mn approx. 570 g / mol; hydrogenated, Croda, 41334 Nettal, Germany (abbreviated as DFA) Sodium 2-ethylhexanoate, 97%, CAS 19766-89-3; Sigma-Aldrich, Munich, Germany Chlorobenzene: (CAS: 108-90-7), Sigma-Aldrich, 99.8%.

[0112] Analysis method: Solution viscosity: The relative solution viscosity (ηrel; also known as etarel) was determined at 25°C using an Ubbelohde viscometer in dichloromethane at a concentration of 5 g / L. The determination was performed according to DIN 51562-3; 1985-05. The flow time of the polyester carbonate under test was measured using the Ubbelohde viscometer to subsequently determine the viscosity difference between the polymer solution and its solvent. For this purpose, the Ubbelohde viscometer was first calibrated using measurements with pure solvents dichloromethane, trichloroethylene, and tetrachloroethylene (always at least 3 measurements, up to 9 measurements). Formal calibration was then performed using dichloromethane. The polymer sample was then weighed, dissolved in dichloromethane, and the flow time of this solution was measured three times. The average flow time was corrected using the Hagenbach correction method, and the relative solution viscosity was calculated.

[0113] Determination of glass transition temperature: The glass transition temperature was determined by dynamic differential scanning calorimetry (DSC) under nitrogen atmosphere at a heating rate of 10 K / min, in accordance with DIN EN ISO 11357-1:2009-10 and ISO 11357-2:2013-05 standards. The glass transition temperature (Tg) was measured as an inflection point during the second heating process.

[0114] The color of the polyester carbonate was determined by the same person through visual inspection.

[0115] 13 C10 NMR spectroscopy: Measurements were performed on a Bruker Avance NEO 600 MHz NMR spectrometer. Measurements were performed in CDCl3.

[0116] Preparation of reactants: Preparation of tetrabutylphosphonium acetate 483.38 g of tetrabutylphosphonium hydroxide aqueous solution (mass ratio: 40%) was pre-loaded into an Erlenmeyer flask. Approximately 40 mL (0.7 mol) of pure acetic acid was then added dropwise until the pH reached approximately 6. Water was removed by distillation at 80 °C and <0.2 mbar. 200 mL of isopropanol, zeolite (4A) for drying, and 0.5 g of activated carbon for purification were added, and the mixture was allowed to stand in a sealed container for at least 12 hours. The product was then filtered and concentrated to a minimum volume at 80 °C and <0.2 mbar. Upon cooling in an airtight container, the product crystallized at approximately 40 °C. Color: Light brown.

[0117] Example 1 (According to the present invention; polyester carbonate prepared from isosorbide, cyclohexane-1,4-dicarboxylic acid and 2-butyl-2-ethylpropane-1,3-diol; sequential one-pot method) 17.22 g (0.10 mol) cyclohexane-1,4-dicarboxylic acid, 64.27 g (0.30 mol) diphenyl carbonate, 0.0023 g (20 ppm) DMAP and 30 µl of lithium hydroxide aqueous solution [β(LiOH) = 100 g / L] were pre-loaded into a flask equipped with a short-path separator.

[0118] The mixture was evacuated and inertized four times with nitrogen to remove oxygen, melted, and heated to 160°C under standard pressure with stirring.

[0119] Once the temperature is reached, check if carbon dioxide is produced (using a bubble counter).

[0120] Once carbon dioxide production decreases, gradually increase the temperature to 210°C until CO2 production further decreases and eventually stops. Phenol is now also distilled off by increasing the temperature.

[0121] Now purge with nitrogen and cool the reaction mixture to ambient temperature. Add 26.83 g (0.1836 mol) of isosorbide and 3.27 g (0.02 mol) of 2-butyl-2-ethylpropane-1,3-diol to the reaction mixture.

[0122] Now, the oxygen in the mixture is removed by vacuuming and inertizing it with nitrogen four times. The temperature is then gradually increased back to 210°C over 20 minutes.

[0123] After a holding period of 10 minutes at 210°C, the temperature is raised to approximately 235°C, during which more phenol is distilled off. Once no more distillate is formed, the pressure is carefully and gradually reduced to <1 mbar over 45 minutes to allow for distillation as continuously as possible. Condensation is then carried out for an additional 10 minutes at a pressure of 0.1 to 0.5 mbar and a low rotation speed.

[0124] A slightly yellow, transparent polymer was obtained. The solution viscosity is shown in Table 1.

[0125] Example 2 (According to the present invention, sequential one-pot method; high catalyst content) This embodiment was carried out in the same manner as Example 1. Instead of 20 ppm, 100 ppm DMAP (0.011 g) was used.

[0126] A pale yellow polymer was obtained. The solution viscosity is shown in Table 1.

[0127] Example 3 (Comparative Example, One-Pot Method) 26.83 g (0.1836 mol) isosorbide, 3.27 g (0.02 mol) 2-butyl-2-ethylpropane-1,3-diol, 17.22 g (0.10 mol) cyclohexane-1,4-dicarboxylic acid, 64.27 g (0.30 mol) diphenyl carbonate, 0.0023 g (20 ppm) DMAP and 30 µl of lithium hydroxide aqueous solution [β(LiOH) = 100 g / L] were pre-loaded into a flask equipped with a short-path separator.

[0128] The mixture was evacuated and inertized four times with nitrogen to remove oxygen. The mixture was melted and heated to 160°C under stirring at standard pressure. Carbon dioxide was continuously generated above approximately 140°C. As gas release decreased, the temperature was gradually increased to 210°C. After CO2 generation ceased, a clear, slightly yellow solution was present.

[0129] The temperature is now raised to 235°C, where phenol is distilled off. Once no more distillate forms, the pressure is carefully and gradually reduced to <1 mbar over 45 minutes to allow for distillation as continuously as possible. Condensation is then carried out for another 10 minutes at 0.1 to 0.5 mbar and a low rotation speed.

[0130] A brown, transparent polymer was obtained. The solution viscosity is shown in Table 1.

[0131] Example 4 (According to the present invention, a sequential one-pot process using CHDA, DFA, and TCD-diethanol) 16.96 g (0.9850 mol) of cyclohexane-1,4-dicarboxylic acid, 44.99 g (0.21 mol) of diphenyl carbonate, 0.855 g (0.0015 mol) of dimer fatty acid and 0.0057 g (50 ppm) of DMAP were pre-loaded into a flask equipped with a short-path separator.

[0132] The mixture was evacuated and inertized four times with nitrogen to remove oxygen, melted, and heated to 160°C under standard pressure with stirring.

[0133] Once this temperature is reached, check for carbon dioxide production (using a bubble counter). Once carbon dioxide production decreases, gradually increase the temperature to 210°C until CO2 production further decreases and eventually stops. Phenol is now also distilled off by increasing the temperature.

[0134] Now purge with nitrogen and cool the reaction mixture to ambient temperature. Add 25.34 g (0.1734 mol) isosorbide, 6.01 g (0.0306 mol) TCD alcohol, 19.28 g (0.09 mol) DPC and 20 µl of lithium hydroxide aqueous solution [β(LiOH) = 100 g / L] to the reaction mixture.

[0135] Now, the oxygen in the mixture is removed by vacuuming and inertizing it with nitrogen four times. The temperature is then gradually increased back to 210°C over 20 minutes.

[0136] After a holding period of 10 minutes at 210°C, the temperature is raised to approximately 235°C, during which more phenol is distilled off. Once no more distillate is formed, the pressure is carefully and gradually reduced to <1 mbar over 45 minutes to allow for distillation as continuously as possible. Condensation is then carried out for an additional 10 minutes at 0.1 to 0.5 mbar and a low rotation speed.

[0137] A slightly yellow, transparent polymer was obtained. The solution viscosity was 1.271.

[0138] Table 1: Eta rel color Catalyst concentration DMAP Reaction time of method step (i)* Example 1 According to the present invention 1.26 pale yellow 20 ppm 82 minutes Example 2 According to the present invention 1.38 yellow 100 ppm 90 minutes Example 3 contrast 1.11 brown 20 ppm 270 minutes Example 4 According to the present invention 1.271 pale yellow 50 ppm 95 minutes * Those skilled in the art will know that the absolute time of method step (i) can be influenced and optimized by temperature control; however, they will also know that the reaction times differ so greatly, for example, between Examples 1 and 2 and Comparative Example 3, that it is unlikely to achieve an optimized method scheme to keep them consistent.

[0139] Example 1 of the present invention demonstrates that a relatively high molecular weight and a very light-colored product can be prepared at an extremely low catalyst concentration (only one-fifth of the concentration used in Example 2). Higher catalyst concentrations can significantly increase the molecular weight; however, the color is slightly impaired, but still within acceptable limits. Conversely, the comparative examples show that the polymer in the one-pot synthesis has a significantly poorer color. Furthermore, it is disadvantageous that high molecular weights cannot be obtained at low catalyst contents. Moreover, it can be seen that, under the operating mode of the present invention and with the same catalyst concentration, the reaction time required for method step (i) is significantly shorter than that of the conventional one-pot method (compared to Example 3 in Example 1).

[0140] Example 5 (Sequential construction of polymer structures according to the present invention) 6.89 g (0.04 mol) cyclohexane-1,4-dicarboxylic acid, 6.65 g (0.04 mol) terephthalic acid, 34.96 g (0.163 mol) diphenyl carbonate, 0.027 g (250 ppm) DMAP and 30 μl of lithium hydroxide aqueous solution [β(LiOH) = 100 g / L] were pre-loaded into a flask equipped with a short-path separator and a dropping funnel.

[0141] Oxygen was removed from the mixture by vacuuming and purging with nitrogen four times. The mixture was melted and heated to 160°C under stirring at standard pressure. The mixture was stirred at 160°C for 50 minutes, at 175°C for 50 minutes, at 190°C for 30 minutes, and at 210°C for 50 minutes. During this process, carbon dioxide was continuously generated.

[0142] Once no more gas is generated and the solution becomes clear, the pressure is reduced to approximately 10 mbar to remove phenol and excess diphenyl carbonate. The reaction mixture is then purged with nitrogen and cooled to 180°C. 5.77 g (0.04 mol) of cyclohexane-1,4-diethanol is added to the reaction mixture. The temperature is gradually increased again to 210°C. The pressure is now reduced to approximately 250 mbar. During this process, phenol is continuously removed.

[0143] Once no more distillate is formed, the mixture is purged with nitrogen, and 23.62 g (0.162 mol) of isosorbide and 25.71 g (0.12 mol) of diphenyl carbonate are pre-loaded into a dropping funnel. The mixture is melted using a hot air gun and then added dropwise to the mixture.

[0144] The temperature was gradually increased to 235°C, while the pressure was carefully and gradually decreased to approximately 1 mbar. The reaction mixture was stirred for 10 minutes at the lowest pressure. The product was then removed. A deep orange, transparent polymer with an etarel of 1.262 was obtained.

[0145] Example 6 (Comparative example, one-pot method using unregulated polymers) 20.66 g (0.12 mol) cyclohexane-1,4-dicarboxylic acid, 70.15 g (0.48 mol) isosorbide, 179.95 g (0.84 mol) diphenyl carbonate, 17.31 g (0.12 mol) cyclohexane-1,4-diethanol, 19.94 g (0.12 mol) terephthalic acid, 0.077 g DMAP (4-dimethylaminopyridine; 250 ppm based on raw materials) and 0.009 g lithium hydroxide in aqueous solution (90 µl LiOH aqueous solution (100.0 g / l)) were pre-loaded into a flask equipped with a short-path separator.

[0146] The mixture was evacuated and purged with nitrogen four times to remove oxygen. The mixture was then melted and heated to 160°C under standard pressure with stirring.

[0147] The mixture was stirred at 160°C for 20 minutes, at 175°C for 20 minutes, at 190°C for 15 minutes, and at 210°C for 30 minutes. During this process, carbon dioxide was continuously generated.

[0148] Once no more gas was generated and the solution became clear, the temperature was raised to 225°C to distill off the phenol. As the phenol distillation decreased, the temperature was raised to 235°C, and the pressure was slowly reduced to approximately 1 mbar over 1 hour to maintain distillation. The reaction mixture was stirred at the minimum pressure for 10 minutes. The product was then removed. An orange polymer with an etarel of 1.286 was obtained. Further results are shown in Table 2.

[0149] Table 2: <![CDATA[ 13 C-NMR NMR]]> Tg Example 5 According to the present invention CHDM carbonate-free 142℃ Example 6 contrast Detectable CHDM carbonates 131℃

[0150] As shown in Table 2, the polymers employing the sequential operation mode do not contain CHDM carbonate groups and therefore exhibit different structures. This is also reflected in the varying glass transition temperatures.

[0151] Experiment 7 (based on the present invention) 25.65 g (0.045 mol) of dimer fatty acid (hydrogenated), 39.52 g (0.1845 mol) of diphenyl carbonate and 0.0020 g (30 ppm) of DMAP were pre-loaded into a flask equipped with a short-path separator. The mixture was evacuated and inertized four times with nitrogen to remove oxygen, melted, and heated to 160 °C under stirring at standard pressure.

[0152] Once the temperature is reached, check if carbon dioxide is produced (bubble counter).

[0153] Once carbon dioxide production decreases, the temperature is gradually increased to 240°C until CO2 production further decreases and eventually stops. Phenol is now also distilled off by increasing the temperature.

[0154] The mixture was then purged with nitrogen and cooled to ambient temperature. 111.80 g (0.765 mol) isosorbide, 17.67 g (0.09 mol) tricyclodecanediethanol, 157.15 g (0.7335 mol) diphenyl carbonate and 34 µl of lithium hydroxide aqueous solution [β(LiOH) = 100 g / L] were added to the reaction mixture.

[0155] Now, the oxygen in the mixture is removed by vacuuming and purging with nitrogen four times. The temperature is then gradually increased back to 210°C over 20 minutes.

[0156] After a holding period of 10 minutes at 210°C, the temperature was increased to approximately 235°C, during which more phenol was distilled off. Once no more distillate was formed, the pressure was carefully and gradually reduced to <1 mbar over 45 minutes to allow for distillation as continuously as possible. Condensation was then carried out for an additional 10 minutes at low speeds, from 0.1 to 0.5 mbar. A pale yellow polymer with an etarel of 1.247 was obtained.

[0157] Experiment 8 (Preparation of Diphenyl Dimeric Fatty Acid Esters) 142.50 g (0.250 mol) of hydrogenated dimer fatty acid, 107.32 g (0.501 mol) of diphenyl carbonate and 0.0025 g (100 ppm) of DMAP were pre-loaded into a flask equipped with a short-path separator. The mixture was evacuated and inertized four times with nitrogen to remove oxygen, melted, and heated to 160 °C under stirring at standard pressure.

[0158] Carbon dioxide is produced above approximately 140°C. As the volumetric flow rate decreases, the temperature gradually increases to a maximum of 240°C. The increased temperature also distills off phenol. Once gas production ceases, the pressure gradually decreases to approximately 1 mbar. The reaction continues in this manner until no more phenol is produced.

[0159] Once the orange-yellow product has cooled, pour it out. The color of the product indicates that the catalyst is still contained within it.

[0160] Experiment 9 (based on the present invention) 118.37 g (0.810 mol) isosorbide, 8.85 g (0.045 mol) tricyclodecanediethanol, 175.25 g (0.8181 mol) diphenyl carbonate and 34 µl of lithium hydroxide aqueous solution [β(LiOH) = 100 g / L] were pre-loaded into a 250 mL three-necked flask.

[0161] The mixture was evacuated and inertized four times with nitrogen to remove oxygen, melted, and heated to 160°C under standard pressure with stirring.

[0162] After reaching this temperature, 32.49 g (0.045 mmol) of diphenyl dimeric fatty acid ester from Experiment 8 was completely added using a dropping funnel.

[0163] After a holding period of 10 minutes at 210°C, the temperature was increased to approximately 235°C, during which more phenol was distilled off. Once no more distillate was formed, the pressure was carefully and gradually reduced to <1 mbar over 45 minutes to allow for distillation as continuously as possible. Condensation was then carried out for an additional 10 minutes at low speeds at 0.1 to 0.5 mbar. A slightly yellow polymer with an etarel of 1.281 was obtained.

[0164] Experiment 10 (based on the present invention) 32.49 g (0.045 mol) of diphenyl dimer fatty acid, 111.80 g (0.765 mol) of isosorbide, 17.67 g (0.09 mol) of tricyclodecanediethanol, 177.21 g (0.8272 mol) of diphenyl carbonate, 900 µL of sodium 2-ethylhexanoate aqueous solution [β = 0.5 g / L] and 150 µL of tetrabutylphosphonium acetate / chlorobenzene solution (100 g / L) from Example 8 were pre-loaded into a flask equipped with a short-path separator.

[0165] The mixture was evacuated and inertized four times with nitrogen to remove oxygen, melted, and heated to 160°C under standard pressure with stirring.

[0166] The temperature will be gradually increased to 210°C over 30 minutes.

[0167] The temperature was then raised to approximately 235°C, during which more phenol was distilled off. Once no more distillate formed, the pressure was carefully and gradually reduced to <1 mbar over 45 minutes to allow for distillation as continuously as possible. Condensation was then carried out for another approximately 10 minutes at a low speed and at 0.1 to 0.5 mbar. A slightly yellow polymer with an etarel of 1.298 was obtained.

Claims

1. A method for producing polyester carbonate via a melt transesterification reaction, comprising the following steps in sequence: (i) Condensing at least one dicarboxylic acid, preferably at least one aliphatic dicarboxylic acid, with at least one diaryl carbonate in the presence of at least one catalyst, wherein chemical compounds eliminated during the condensation process are removed to provide mixture (I). Optional method step (ii), which includes (ii) Contacting at least one diol with the mixture (I) obtained directly from step (i) of method, and at least partially condensing the compounds present in step (ii), wherein chemical compounds eliminated during the condensation process are removed to provide mixture (II). (iii) Contacting at least one 1,4:3,6-disodehydrated hexitol and optionally a further diaryl carbonate with a mixture (I) obtained directly from method step (i), or contacting it with a mixture (II) obtained directly from method step (ii) when performing method step (ii), and performing condensation, wherein the chemical compounds eliminated in the reaction are removed.

2. The method as described in claim 1, characterized in that, Before starting method step (ii), or, if there is no method step (ii), before starting method step (iii), the condensation reaction in method step (i) must be at least 70% complete.

3. The method of any one of claims 1 or 2, wherein, The at least one dicarboxylic acid is selected from compounds of formulas (1), (2), and (3), furanyl dicarboxylic acid, naphthalene dicarboxylic acid, phthalic acid, isophthalic acid, and terephthalic acid, wherein (1)， (2)， In equations (1) and (2), B is independently a CH2 group or a heteroatom selected from O and S, preferably a CH2 group or an oxygen atom. R1 is each independently a single bond or an alkylene group having 1 to 10 carbon atoms, preferably a single bond or an alkylene group having 1 to 5 carbon atoms, especially a single bond; and n is a value from 0 to 3, preferably 0 or 1, and (3) In equation (3), each R 2 Each of the above is an aliphatic group having 16 to 44 carbon atoms, which optionally contains one or more double bonds.

4. The method of claim 3, wherein, R in formula (3) 2 is represented by the following formula (R2A): (R2A), Wherein Y is a bridging structure selected from alkylene groups having 1 to 4 carbon atoms, alkylidene groups having 1 to 4 carbon atoms, and cycloalkylene groups having 4 to 12 carbon atoms, wherein the cycloalkylene group optionally contains one or more double bonds and / or optionally is fused to one or more other cycloalkylene groups, wherein the one or more other cycloalkylene groups optionally each have one or more double bonds. wherein R adjacent to the bridging structure 11 groups are attached to any position of the bridging structure, and Each R 11 Each is independently an alkylene group having 1 to 12 carbon atoms or an alkylidene group having 1 to 12 carbon atoms, wherein the structure of formula (R2A) contains 16 to 44 carbon atoms, and wherein the positions marked with "~" in formula (R2A) are the positions of the (C=O) groups shown in formula (3).

5. The method of claim 4, wherein, Equation (R2A) is represented by one of equations (R2Aa), (R2Ab), (R2Ac), or (R2Ad). (R2Aa), (R2Ab), (R2Ac) and (R2Ad), Each R 11 As defined in claim 4, each ring of formula (R2Ac) optionally has one or two double bonds, and each ring of formula (R2Ad) optionally contains one or two double bonds independently of each other.

6. The method of any one of claims 1 to 5, wherein, The diol in step (ii) is aliphatic or alicyclic.

7. The method of claim 6, wherein, The diol in step (ii) is selected from cyclohexane-1,2-diol, cyclohexane-1,3-diol, cyclohexane-1,4-diol, cyclohexane-1,2-diethanol, cyclohexane-1,3-diethanol, cyclohexane-1,4-diethanol, 2,2-bis(4-hydroxycyclohexyl)propane, tetrahydrofuran-2,5-diethanol, 2,2,4,4-tetramethylcyclobutane-1,3-diol, cyclobutane-1,1-diyldiethanol, [8-(hydroxymethyl)-3-tricyclo[5.2] .1.02,6]decyl]methanol, 2-butyl-2-ethylpropane-1,3-diol, 2-(2-hydroxyethoxy)ethanol, 2,2,4-trimethylpentane-1,3-diol, 2,2-dimethylpropane-1,3-diol, propane-1,2-diol, propane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, octane-1,8-diol, 1,4:3,6-dihydrohexitol and compounds of formula (4), (4) Where each r and each s are independent numbers from 0 to 4, and each R 3 Each of them has an independent structure consisting of (R3A), (R3B), (R3C), and (R3D). (R3A) Where a is 0 or 1, (R3B) Where b is 0 or 1, (R3C) (R3D) wherein the positions marked with a "~" in formulae (R3A) to (R3D) are the positions of (CH2) as indicated in formula (4) r group or (CH2) s group.

8. The method according to any one of claims 1 to 7, characterized in that, The diaryl carbonate in method step (i) and / or the optional further diaryl carbonate in method step (ii) are selected from compounds of formula (5). (5) wherein R, R' and R" can each, independently of one another, be identical or different and are hydrogen, optionally branched C1-C 34 alkyl, C7-C 34 alkylaryl, C6-C 34 aryl, nitro, carbonyl-containing groups, carboxyl-containing groups or halogen groups.

9. The method according to any one of claims 1 to 8, characterized in that, In method step (i), 2.01 to 2.5 moles, more preferably 2.05 to 2.2 moles, of diaryl carbonate are used per mole of the at least one dicarboxylic acid, and further diaryl carbonate is added in method step (iii).

10. The method according to any one of claims 1 to 9, characterized in that, The catalyst used in step (i) is an inorganic base and / or an organic catalyst.

11. The method as described in claim 10, characterized in that, The catalyst used in step (i) is selected from alkylamines, imidazoles (derived from), guanidine-derived bases, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, hexamethylphosphorimide triamide, 1,2-dimethyl-1,4,5,6-tetrahydropyridine, 7-methyl -1,5,7-triazabicyclodec-5-ene, ethylimidazolium, N,N-diisopropylethylamine (Hünig base), pyridine, 1,1,3,3-tetramethylguanidine (TMG), 4-dimethylaminopyridine and its derivatives, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), and mixtures thereof.

12. The method according to any one of claims 1 to 11, characterized in that, The amount of catalyst used in step (i) is 1 to 1000 ppm based on the weight of dicarboxylic acid and diaryl carbonate.

13. The method according to any one of claims 1 to 12, characterized in that, In step (iii), at least one other diol is also contacted with the mixture (I) obtained directly from step (i), or with the mixture (II) obtained directly from step (ii) when step (ii) is performed.

14. A polyester carbonate obtained by the method of any one of claims 1 to 13, wherein the method must include method step (ii).

15. A molded article comprising the polyester carbonate as described in claim 14.

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