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

Abstract

The present invention relates to a process for producing, by way of melt transesterification, a polyester carbonate containing at least one 1,4:3,6-dianhydrohexitol, the process comprising a defined temporal sequence of reactions. The obtained polyester carbonates are of good color and have high molecular weights. The invention further relates to a polyester carbonate which can be obtained using the process of the invention as well as to a molding containing the polyester carbonate according to the invention.

Description

[0001] SEQUENTIAL PROCESS FOR THE PREPARATION OF POLYESTER CARBONATES CONTAINING 1,4:3,6-DIANHYDROHEXITOL

[0002] The present invention relates to a process for producing a polyester carbonate containing at least one 1,4:3,6-dianhydrohexitol by melt transesterification, wherein the process comprises a defined temporal sequence of reactions. The resulting polyester carbonates have a good color and high molecular weights. Furthermore, the present invention relates to a polyester carbonate obtained by the described process and to a molded article containing this polyester carbonate.

[0003] Polyesters, polycarbonates, and polyestercarbonates are known to exhibit good mechanical properties, heat resistance, and weathering resistance. Each polymer group exhibits certain key characteristics, depending on the monomers used, that distinguish such materials. Polycarbonates, for example, exhibit particularly good mechanical properties, whereas polyesters often exhibit better chemical resistance. Polyestercarbonates exhibit property profiles from both of these groups, depending on the monomers selected.

[0004] Aromatic polycarbonates and polyesters, in particular, exhibit weaknesses in terms of aging and weathering resistance. For example, UV light absorption leads to yellowing and possibly embrittlement of these thermoplastic materials. Aliphatic polycarbonates and polyester carbonates exhibit better properties in this regard, particularly better aging and / or weathering resistance, as well as better optical properties (e.g., better transmission).

[0005] The disadvantage of aliphatic polycarbonates or polyester carbonates is often their low glass transition temperature. This low glass transition temperature limits their application possibilities and means that aliphatic polycarbonates or polyester carbonates often cannot be considered a full replacement for traditional aromatic polycarbonates or polyester carbonates.

[0006] In addition, processes for producing aliphatic polycarbonates, polyesters, and polyester carbonates present different challenges than corresponding processes using aromatic starting materials or products. Polyesters made from 1,4-cyclohexanedimethanol and 1,4-cyclohexanedicarboxylic acid, for example, are produced starting from the dimethyl ester of the diacid. However, phenyl esters are significantly more reactive in the transesterification reaction than their aliphatic analogues. EP 3026074 A1 and EP 3248999 A1 describe processes for producing polyester carbonates using phenyl ester as an intermediate step. However, these phenyl esters are produced starting from the corresponding acid chlorides. These, in turn, are produced using phosgene. The phosgene process also requires the use of solvents—usually halogenated solvents—which must be laboriously recycled or disposed of.Therefore, it is advantageous to provide a phosgene-free process that, ideally, also does not require the use of solvents. Furthermore, additional process steps for purification or isolation of the intermediates are necessary, making the described processes ecologically and economically complex.

[0007] WO2020 / 126806 A1 describes a process for producing polyester carbonates that requires neither the use of phosgene nor solvents. This process has the advantage of delivering high molecular weights of the desired polyester carbonates, since achieving high molecular weights of aliphatic polyesters or polyester carbonates in a melt reaction still represented a challenge in the prior art. This process has advantages in terms of simple installation and low effort regarding workup steps, since intermediates do not require laborious isolation and purification. However, this process requires a certain concentration of highly effective catalysts such as 4-dimethylaminopyridine to achieve sufficiently high molecular weights (see comparative examples of the present invention).However, such catalysts can have a corrosive effect at higher concentrations, so it is advantageous to reduce the concentration of such catalysts. Reducing the catalyst quantity is also advantageous for cost reasons. Higher catalyst concentrations can also result in the final product having a poorer color (see examples of the present invention). If catalyst residues remain in the final product, this can also lead to poor further processing of the product and, for example, to a reduction in molecular weight during injection molding. A further disadvantage of the one-pot process described therein is that the polymer architecture cannot be controlled. If, as defined, all reactants are initially introduced in a three-pot process, only statistically structured polymers can be obtained.Depending on the reactivity of the monomers, blocks made up of the more reactive monomers may preferentially form, with the less reactive monomers being incorporated later. The precise incorporation cannot be controlled in the one-pot process.

[0008] WO2021 / 122509 A1 describes a process for producing a polyester carbonate, wherein a diester is first prepared from a linear or cycloaliphatic dicarboxylic acid with a carbonate. Catalyst concentrations of 0.005 to 0.02 wt.%, based on the components used in the process step, are disclosed. This diester is separated from the mixture of the first process step and purified. Only then is a dihydroxy compound, such as 1,4:3,6-dianhydrohexitol, and a diaryl carbonate added, followed by the reaction to form the polymer. Such a process is occasionally referred to below as a / w o-.s / c / j process. In this document, a diester isolation step is therefore always mandatory, which is complex and thus associated with ecological and economic disadvantages.

[0009] Based on this prior art, the present invention was therefore based on the object of solving the problems of the prior art described above. In particular, the object of the invention was to provide a process for producing a polyester carbonate by melt transesterification, which is particularly simple and at the same time yields a polyester carbonate of high quality and good properties. The process should be as ecologically and economically viable as possible. This preferably means that the process comprises as few process steps as possible. In particular, the apparatus complexity of the synthesis and / or the effort associated with the workup of intermediates and / or end products should be kept as low as possible. Furthermore, it is preferred that a polyester carbonate is obtained at the same time which has a good color and / or a sufficiently high molecular weight.A "sufficiently high molecular weight" is preferably understood as a polymer with a relative solution viscosity above 1.20, particularly preferably from 1.21 to 1.65, further preferably from 1.22 to 1.63, particularly preferably from 1.23 to 1.62, and especially preferably from 1.26 to 1.55. Likewise, the process should preferably enable the targeted and controlled synthesis of the polyester carbonate.

[0010] At least one, preferably all, of the above-mentioned objects have been achieved by the present invention. Surprisingly, it was found that the process sequence according to the invention made it possible to reduce the number of process steps and, at the same time, to obtain a polyester carbonate of good quality and with good properties. This surprisingly provided an economically and ecologically advantageous process. In particular, it was found that it is advantageous to initially produce at least some of a diester in the first process step. However, this does not need to be further purified; rather, the mixture possibly obtained by a partially incomplete reaction can react further immediately. This is surprising, since the prior art suggests the need to purify the diester in order to obtain a polyester carbonate with good color.Only in a second step are the 1,4:3,6-dianhydrohexitol and optionally the diaryl carbonate added. It was found that, despite the lack of isolation of the diester, the side reactions do not negatively affect the quality and / or molecular weight buildup of the polymer. Thus, the process according to the invention is less complex, and the additional equipment required (tanks, pipes, evaporators, etc.) for isolating the diester is eliminated. This makes the process according to the invention economically advantageous. At the same time, however, it was also found that the color of the polymer can be improved by separating the reaction in process step (i) according to the invention from the reaction in process step (iii), in particular by later adding the 1,4:3,6-dianhydrohexitol. Surprisingly, it was possible to reduce the catalyst concentration in process step (i) according to the invention.This is associated with both economic and ecological advantages. Despite the reduction in catalyst concentration, the reaction in process step (i) was still sufficiently rapid, preferably even faster than in the classic one-pot process (in which at least the 1,4:3,6-dianhydrohexitol is still present in process step (i)). A short reaction time has many advantages, particularly with regard to the energy used, the yield per unit time (economic advantages), the reduction in the formation of by-products and / or decomposition products, and also the possibility of efficiently conducting a reaction continuously.Overall, the process sequence according to the invention made it possible to obtain a process which, despite the use of low catalyst concentrations, provides polyester carbonates with comparably good color, preferably improved color compared to the prior art, and comparably good molecular weights, preferably higher molecular weights than the prior art. The lower catalyst concentration is also associated with ecological and economic advantages (see above). The good color of the polyester carbonates is an indication of a low concentration of by-products and / or decomposition products. These can also, for example, reduce the thermal stability of the polymer or the mechanical properties. Thus, the polyester carbonates provided by the process according to the invention have comparable, preferably improved, thermal stability and mechanical properties to the prior art.

[0011] In particular, the present invention offers the advantage of enabling a targeted construction of the polymer structure. Firstly, the process according to the invention allows the sequential addition of catalysts to the various process steps. This enables the targeted presence of catalysts only in process steps where the catalyst(s) are to be effective. At the same time, it is highly beneficial to react certain monomers first, regardless of their reactivity, and to incorporate them into the polyester carbonate as blocks or pre-reacted products such as trimers. This allows for better control of the polymer architecture. This can lead to targeted improvements in properties. For example, special monomers with sensitive end groups can be reacted first in process step (ii) according to the invention in order to protect them from thermal influences and oxidation.Furthermore, the process according to the invention makes it possible to bridge only certain monomers via ester groups, whereas other monomers may be preferentially bridged via carbonate units. This can also be advantageous for the property profile of the resulting polyester carbonate. If, for example, certain ester groups are susceptible to hydrolysis, it makes sense to limit the proportion of these ester groups in the resulting polyester carbonate. This means that it is advantageous to be able to control the polymer architecture during the process according to the invention. Furthermore, it has been found that, since the reaction takes place under vacuum, at least in certain process steps, the vapors frequently contain a mixture of various components. These usually comprise a mixture of condensation products, reactants, various catalysts, and by-products.According to the invention, the separation of these vapor mixtures is simplified because the different process steps result in more defined vapors. This makes the separation of the vapors easier overall.

[0012] According to the invention, a process for producing a polyester carbonate by melt transesterification is provided, comprising in this order

[0013] (i) Condensation of 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 with removal of the chemical compound split off during the condensation to provide a mixture (I), optionally a process step (ii) comprising

[0014] (ii) bringing at least one diol into contact with the mixture (I) obtained directly from process step (i), and at least partially condensing the compounds present in process step (ii) with removal of the chemical compound split off during the condensation to provide a mixture (II),

[0015] (iii) bringing into contact at least one 1,4:3,6-dianhydrohexitol and optionally further diaryl carbonate with the mixture (I) obtained directly from process step (i) or, if a process step (ii) has been carried out, with the mixture (II) obtained directly from process step (ii) and condensing to remove the chemical compound split off during the reaction.

[0016] Likewise, according to the invention, a process for producing a polyester carbonate by melt transesterification is provided, comprising in this order

[0017] (i) Condensation of 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 with removal of the chemical compound split off during the condensation to provide a mixture (I), optionally a process step (ii) comprising

[0018] (ii) adding at least one diol to the mixture (I) obtained directly from process step (i), and at least partially condensing the compounds present in process step (ii) with removal of the chemical compound split off during the condensation to provide a mixture (II),

[0019] (iii) adding at least one 1,4:3,6-dianhydrohexitol and optionally further diaryl carbonate to the mixture (I) obtained directly from process step (i) or, if a process step (ii) has been carried out, to the mixture (II) obtained directly from process step (ii) and condensing to remove the chemical compound split off during the reaction.

[0020] The process of melt transesterification is known to those skilled in the art. Reference can be made, for example, to Schnell, "Chemistry and Physics of Polycarbonates," Polymer Reviews, Volume 9, Interscience Publishers, New York, London, Sydney 1964. In the melt transesterification process, the starting materials are transesterified in the melt with the aid of suitable catalysts and, if necessary, other additives. The temperatures obviously depend on the melting points of the materials used.

[0021] According to the invention, the term “bringing into contact” is used. This is intended to include embodiments in which one component / mixture, etc., is added to another component / mixture, etc., as well as the reverse order. How such contact between components and / or mixtures is established is known to those skilled in the art. This can be done, for example, by adding a component and / or a mixture, initially introducing a component and / or a mixture, mixing a component and / or a mixture, adding a component and / or a mixture dropwise, etc. It is apparent to those skilled in the art that the term “adding,” as it is occasionally used according to the invention, can be understood as a synonym for “bringing into contact.” It is also apparent to those skilled in the art that the term “adding,” as it is occasionally used according to the invention, can be encompassed by the term “bringing into contact.”is a sub-form of “bringing into contact”.

[0022] The term "condensation" or "condensation" is also familiar to those skilled in the art. Preferably, "condensation" refers to a reaction in which two molecules (of the same substance or different substances) combine to form a larger molecule, with a molecule of a chemically simple substance being split off. This compound split off during the condensation is removed in process step (i) or similarly in process steps (ii) and / or (iii).

[0023] According to the invention, in process step (i), at least the condensation of at least one dicarboxylic acid with at least one diaryl carbonate takes place in the presence of at least one catalyst. This is preferably an aliphatic dicarboxylic acid.

[0024] Likewise preferably, the at least one dicarboxylic acid is selected from the group consisting of the compounds represented by formula (1), (2) and (3), furandicarboxylic acid, naphthalenedicarboxylic acid, phthalic acid, isophthalic acid and terephthalic acid, where wherein in formulas (1) and (2) B each independently represents a CH2 group or a heteroatom selected from the group consisting of O and S, preferably a CH2 group or an oxygen atom,

[0025] Ri each independently represents 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, particularly preferably a single bond, and n is a number between 0 and 3, preferably 0 or 1, and where in formula (3) each R 2independently represent an aliphatic group having 16 to 44 carbon atoms, which may contain one or more double bonds.

[0026] It is preferred that the at least one dicarboxylic acid is an aliphatic dicarboxylic acid, and thus furandicarboxylic acid, naphthalenedicarboxylic acid, phthalic acid, isophthalic acid, and terephthalic acid are deleted from the group described above. Particularly preferably, the at least one dicarboxylic acid is a mixture of at least one aliphatic dicarboxylic acid, preferably selected from the dicarboxylic acids described above, and at least one aromatic dicarboxylic acid, preferably selected from furandicarboxylic acid, naphthalenedicarboxylic acid, phthalic acid, isophthalic acid, and terephthalic acid. Very particular preference is given to the combination of 1,4-cyclohexanedicarboxylic acid and terephthalic acid. Likewise particularly preferred is the combination of dimer fatty acid and terephthalic acid.

[0027] Additionally, other dicarboxylic acids may optionally be present, such as tetradihydro-2,5-furandicarboxylic acid, tetradihydro-2,5-dimethylfurandicarboxylic acid, decahydro-2,4-naphthalenedicarboxylic acid, decahydro-2,5-naphthalenedicarboxylic acid, decahydro-2,6-naphthalenedicarboxylic acid, decahydro-2,7-naphthalenedicarboxylic acid, furandicarboxylic acid, naphthalenedicarboxylic acid, phthalic acid, isophthalic acid, and terephthalic acid. Any desired mixtures can also be used. In addition to the cycloaliphatic acid, small amounts of other aliphatic acids can also be used. For example, selected from the group consisting of 2,2,4-trimethyladipic acid, 2,4,4-trimethyladipic acid, 2,2,5-trimethyladipic acid, and 3,3-dimethylglutaric acid.

[0028] With regard to formulas (1) and (2), it is understood that when Ri represents a single bond, Ri thus comprises zero carbon atoms.

[0029] In particular, it is preferred that the dicarboxylic acid of formula (1) or (2) is selected from the group consisting of 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, tetradihydro-2,5-furandicarboxylic acid, tetradihydro-2,5-dimethylfurandicarboxylic acid, decahydro-2,4-naphthalenedicarboxylic acid, decahydro-2,5-naphthalenedicarboxylic acid, decahydro-2,6-naphthalenedicarboxylic acid, and decahydro-2,7-naphthalenedicarboxylic acid. Any desired mixtures can also be used. 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, or 1,2-cyclohexanedicarboxylic acid are particularly preferred.

[0030] Particularly preferred is each R 2in formula (3) independently of one another represent an aliphatic group having 17 to 44 carbon atoms, particularly preferably having 18 to 44 carbon atoms, particularly preferably having 19 to 44 carbon atoms, particularly preferably having 20 to 44 carbon atoms, particularly preferably having 21 to 44 carbon atoms, particularly preferably having 22 to 43 carbon atoms, particularly preferably having 23 to 42 carbon atoms, particularly preferably having 24 to 41 carbon atoms, particularly preferably having 25 to 40 carbon atoms, particularly preferably having 26 to 39 carbon atoms, particularly preferably having 27 to 38 carbon atoms, particularly preferably having 28 to 37 carbon atoms, particularly preferably having 29 to 37 carbon atoms, particularly preferably having 30 to 37 carbon atoms, particularly preferably having 31 to 37 carbon atoms, particularly preferably having 32 to 37 carbon atoms and very particularly preferably having 33 up to 37 carbon atoms.。

[0031] In the context of the present invention, the term “aliphatic” or “aliphatic group”, unless defined otherwise, refers to a hydrocarbon group which does not contain any aromatic units. However, this group may have one or more double bonds. Furthermore, this group may have one or more cycles. These cycles may be condensed with one another (i.e., for example, one or more carbon atoms may belong to two cycles) or be linked to one another by, for example, alkylene groups or alkylidene groups. This one or more cycles may have one or more double bonds. However, it should be noted that, according to the invention, aromatic cycles are not encompassed by the definition of “aliphatic”. Furthermore, the one or more cycles or the aliphatic group itself may be interrupted by one or more heteroatoms. However, this is less preferred.

[0032] In the context of the present invention, the term "alkyl" or "alkyl group" preferably refers, unless otherwise stated, to an alkane structure from which a hydrogen atom has been removed. The alkyl group according to the present invention can be linear or branched. It is saturated and therefore comprises only single bonds between the adjacent carbon atoms. The alkyl group preferably 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 and the like.The selection of these structures may be limited if the number of carbon atoms is defined differently in the present invention.

[0033] In the context of the present invention, the term "alkylene" or "alkylene group" preferably refers, unless otherwise stated, to a bridging alkane structure from which two hydrogen atoms have been removed from different carbon atoms. In this context, the two hydrogen atoms removed from the two carbon atoms can be removed from any carbon atoms in the alkane structure. This means that the two carbon atoms can be adjacent, but do not necessarily have to be adjacent. An alkylene group can be linear or branched. It is saturated. If the alkylene group comprises only one carbon atom, it is a methylene group (-CH2-), which is linked to the rest of the molecule via two single bonds.The alkylene group preferably 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-methylpentylene, 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, 1-ethyl-2-methylpropylene, and the like. The selection of these structures may be limited if the number of carbon atoms is defined differently within the scope of the present invention.In addition, the alkylene group according to the present invention may optionally contain at least one carbonyl group, optionally contain at least one halogen atom, and / or optionally be interrupted by at least one heteroatom. Examples of such alkylene groups are -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-, and the like. However, the aforementioned structures are less preferred according to the invention. In addition, the term "cycloalkylene group" is also used according to the invention. The above-mentioned statements apply here, with the addition that the group may additionally contain one or more cycles. These cycles can be condensed with each other (i.e., one or more carbon atoms can belong to two cycles) or can be connected to each other, for example, by alkylene groups. This one or more cycles can contain one or more double bonds.In addition, the one or more cycles or the aliphatic group itself can be interrupted by one or more heteroatoms. However, this is less preferred.

[0034] In the context of the present invention, the term "alkylidene" or "alkylidene group" preferably refers, unless otherwise stated, to a bridging alkane structure in which two hydrogen atoms have been removed from the same carbon atom. The alkylidene group optionally comprises at least one carbon-carbon double bond, optionally at least one carbonyl group, and / or optionally at least one halogen atom. The alkylidene group preferably comprises isopropylidene, n-propylidene, isoheptylidene, and the like.

[0035] In the context of the present invention, the term "aralkyl" preferably refers, unless otherwise stated, to a linear, cyclic, or branched alkyl group that is mono-, di-, or polysubstituted by aryl radicals. In the context of the present invention, the term "aryl" preferably refers, unless otherwise stated, to an aromatic hydrocarbon radical. Examples of "aryl" are phenyl, o-, p-, and m-toluyl, naphthyl, phenanthryl, or anthrancenyl.

[0036] In the context of the present invention, the term "alkoxy" or "alkoxy group" preferably refers, unless otherwise stated, to a linear, cyclic, or branched alkyl group that is singly bonded to an oxygen atom (-OR). Alkoxy groups according to the present invention preferably have 1 to 6 carbon atoms. Alkoxy groups particularly preferably include methoxy, ethoxy, α-propoxy, iso-propoxy, n-butoxy, and α-butoxy. / e / - Butoxy, «-pentoxy, 1-methylbutoxy, 2-methylbutoxy, 3-methylbutoxy, neo-pentoxy, 1-ethylpropoxy, cyclohexoxy, cyclopentoxy, «-hexoxy, 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 selection of these structures may be limited if the number of carbon atoms is defined differently within the scope of the present invention.

[0037] Based on the above definitions, the person skilled in the art will be able to understand further definitions not explicitly mentioned above.

[0038] According to the invention, it is preferred that R 2in formula (3) is represented by the following formula (R2A) with

[0039] CH3

[0040] R 11

[0041] - R11— Y— R 11 -

[0042] R11

[0043] CH3 (R2A), where Y is a bridging structure selected from the group consisting of an alkylene group having 1 to 4 carbon atoms, an alkylidene group having 1 to 4 carbon atoms and a cycloalkylene group having 4 to 12 carbon atoms, preferably 4 to 10 carbon atoms, where the cycloalkylene group optionally contains one or more double bonds and / or is optionally condensed to one or more further cycloalkylene groups, where the one or more further cycloalkylene groups optionally each have one or more double bonds, where the R adjacent to the bridging structure 11-groups are bonded to any position of the bridging structure and where each R 11 independently of one another represents an alkylene group having 1 to 12 carbon atoms or an alkylidene group having 1 to 12 carbon atoms, with the proviso that the structure of formula (R2A) comprises 16 to 44 carbon atoms and wherein the positions marked with , in formula (R2A) are the positions at which the (C=O) groups shown in formula (3) are located.

[0044] Particularly preferably, the formula (R2A) is represented by one of the formulas (R2Aa), (R2Ab), (R2Ac) or (R2Ad), with where each R 11 and every has the meanings given for (R2A), the cycle of formula (R2Ac) optionally has one or two double bonds, and each cycle of formula (R2Ad) independently of one another optionally contains one or two double bonds. It is also particularly preferred that R 2in formula (3) is represented by a mixture of at least two different formulas (R2Aa), (R2Ab), (R2Ac), and (R2Ad). This also includes mixtures of different groups that fall under the same formula (for example, two groups that fall under the formula (R2Aa)).

[0045] As explained in more detail above, the cycles of the formulas (R2Ac) and / or (R2Ad) can each contain one or two double bonds. This does not usually involve the formation of an aromatic ring. As explained further below, it may be that when R 2 in formula (3) comprises a mixture of at least two different formulas (R2Aa), (R2Ab), (R2Ac), and (R2Ad), small amounts of aromatic bridging structures Y according to formula (R2A) are also present. However, this is less preferred.

[0046] Particularly preferred is each R 11in the formula (R2A) and / or in the formulas (R2Aa), (R2Ab), (R2Ac) or (R2Ad) independently of one another represent an alkylene group having 1 to 10 carbon atoms, with the proviso that the structure of the formula (R2A) and / or in the formulas (R2Aa), (R2Ab), (R2Ac) or (R2Ad) comprises 16 to 44 carbon atoms.

[0047] It is also preferred that the R 2 , (R2A), (R2Aa), (R2Ab), (R2Ac) and / or (R2Ad) in formula (3) has 21 to 44 carbon atoms. It is equally preferred that the group represented by R 2, (R2A), (R2Aa), (R2Ab), (R2Ac) and / or (R2Ad) in the formula (3) has 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 preferably 33 to 37 carbon atoms.The person skilled in the art is able to transfer this limited number of carbon atoms to the above-mentioned provisions regarding the number of carbon atoms.

[0048] It is particularly preferred that the different R 11 in the formula (R2A) and / or in the formulas (R2Aa), (R2Ab), (R2Ac) or (R2Ad) comprise a different number of carbon atoms.

[0049] Formula (3) is most preferably dimer fatty acid. Those skilled in the art know that dimer fatty acid is a mixture of various acids. The predominant structures are as follows.

[0050] Fully hydrogenated compounds are preferably used. Dimer fatty acid is generally a mixture and is produced by condensing various unsaturated fatty acids. For this purpose, a fatty acid with conjugated double bonds (conjuenic acid) is reacted with other unsaturated fatty acids. Conjugated linoleic acids are particularly preferred for this purpose. The reaction usually takes place by means of a Diels-Alder addition, whereby a partially unsaturated C6 ring is formed. Dimer fatty acid therefore initially comprises at least partially one or more double bonds. The mixture of dimer fatty acids can comprise, in addition to the dimer, trimers and monomers of the fatty acids. Oleic acid and linoleic acid are particularly preferably reacted. The double bonds contained in the dimer fatty acid are usually hydrogenated. Formula (3) is most preferably a dimer fatty acid with 36 carbon atoms.

[0051] Dimer fatty acids are commercially available and are known, for example, under the trade names Pripol 1009, Pripol 1006, Pripol 1025, Radiacid 0960, Radiacid 0975, Radiacid 0976, Radiacid 0977, Radiacid 0978, and Unidyme 18. Pripol and Pripol derivatives are produced, as described above, by oligomerization of unsaturated fatty acids—preferably C18 acids. Dimerization yields a mixture of mono-, di-, and tricarboxylic acids. The monofunctional compounds are usually separated by distillation. Typically, a mixture of 80% difunctional and 20% trifunctional compounds is then 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 comprising predominantly C36 diacid.

[0052] Furthermore, it is preferred that the diaryl carbonate of process step (i) (and / or the optional further diaryl carbonate of process step (ii)) is selected from the group consisting of a compound of formula (5) wherein R, R and R" may each independently be the same or different and represent hydrogen, optionally branched C1-C34 alkyl, C1-C34 alkylaryl, C1-C34 aryl, a nitro group, a carbonyl-containing group, a carboxyl-containing group or a halogen group. The diaryl carbonate of process step (i) and the optional diaryl carbonate of process step (iii) are the same or different, preferably the same.

[0053] Particularly preferably, the at least one diaryl carbonate is diphenyl carbonate, 4-tert-butylphenyl phenyl carbonate, di-(4-tert-butylphenyl) carbonate, biphenyl-4-yl phenyl carbonate, di-(biphenyl-4-yl) carbonate, 4-(1-methyl-1-phenylethyl)-phenyl phenyl carbonate, di-[4-(1-methyl-1-phenylethylj-phenyl] carbonate,

[0054] Bis(methyl salicyl) carbonate, bis(ethyl salicyl) carbonate, bis(propyl salicyl) carbonate, bis(2-benzoylphenyl carbonate), bis(phenyl salicyl) carbonate and / or bis(benzyl salicyl) carbonate. Particularly preferably, the at least one diaryl carbonate is diphenyl carbonate, 4-tert-butylphenyl phenyl carbonate, di-(4-tert-butylphenyl) carbonate, biphenyl-4-yl phenyl carbonate, di-(biphenyl-4-yl) carbonate, 4-(1-methyl-1-phenylethyl)-phenyl phenyl carbonate and / or di-[4-(1-methyl-1-phenylethyl)-phenyl] carbonate.

[0055] Particularly preferably, the at least one diaryl carbonate is diphenyl carbonate.

[0056] Furthermore, according to the invention, at least one catalyst is present in process step (i). This is preferably an inorganic base and / or an organic catalyst. Particularly preferably, the at least one catalyst is an inorganic or organic base with a pKB value of at most 5.

[0057] It is also preferred that the at least one inorganic base or the at least one organic catalyst is selected from the group consisting of lithium, sodium, potassium, cesium, calcium, barium, magnesium, hydroxides, carbonates, halides, phenolates, diphenolates, fluorides, acetates, phosphates, hydrogen phosphates, boranates, tetramethylammonium hydroxide, tetramethylammonium acetate,

[0058] tetramethylammonium fluoride, tetramethylammonium tetraphenylboranate,

[0059] Tetraphenylphosphoniumfluorid, Tetra-phenylphosphoniumtetraphenylboranat,

[0060] Dimethyldiphenylammoniumhydoxid, Tetraethylammoniumhydroxid,

[0061] Cethyltrimethylammoniumtetraphenylboranat, Cethyltrimethylammoniumphenolat,

[0062] Diazabicycloundecen (DBU), Diazabicylononen (DBN), l,5,7-Triazabicyclo-[4,4,0]-dec-5- en, 7-Phenyl-l,5,7-triazabicyclo-[4,4,0]-dec-5-en, 7-Methyl-l,5,7-triazabicyclo-[4,4,0]-dec- 5-en, 7,7'-Hexylidendi-l,5,7-triazabi-cyclo-[4,4,0]-dec-5-en, 7,7'-Decylidendi-l,5,7- triazabicyclo-[4,4,0]-dec-5-en, 7,7'-Dodecyliden-di-l,5,7-tri-aza-bicyclo-[4,4,0]-dec-5-en, die Phosphazen-Base Pl-t-Oct (tert. -Octyl -imino-tris-(dimethylamino)-phosphoran), die Phosphazen-Base Pl-t-Butyl (tert. -Butyl -imino-tris-(dimethylamino)-phosphoran) und 2- tert. -Butylimino-2 -diethylamino- 1 ,3 -dimethyl -perhydro- 1 ,3 ,2-diaza-2-phos-phoran (BEMP) . Es können auch beliebige Mischungen eingesetzt werden.

[0063] Preferably, the catalyst used in process step (i) is selected from the group consisting of alkylamines, imidazole (derivatives), guanidine-derived bases, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-

[0064] 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, ethylimidazole, N,N-di-isopropyl ethylamine (Hünig's base), pyridine, 1,1,3,3-tetramethylguanidine (TMG), 4-dimethylaminopyridine and derivatives, l,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) and mixtures of these substances.

[0065] Particularly preferably, the at least one catalyst in process step (i) is an organic base, preferably those mentioned above, very particularly preferably alkylamines, imidazole (derivatives), guanidine bases such as triazabicyclodecene, DMAP and corresponding derivatives, DBN and DBU, most preferably DMAP. These catalysts have the particular advantage that they can be separated in process step (iii) according to the invention with the chemical compound eliminated during the condensation, for example by means of a vacuum. However, the catalyst preferably remains in mixture (I). According to the invention, it has been found that the catalyst concentration can be kept very low, in particular compared to the classic two-step process and / or three-pot process of the prior art. Therefore, the mixture (I) can be used particularly in comparison to the three-step process and / or three-pot process.s / c / j processes of the prior art have a lower catalyst concentration (whereby in a one-pot process no mixture (I) is formed, since all units constituting the later polymer are already present from the outset; this means that a comparable mixture still comprises other components than the mixture (I); in the / w o-.s / c / j process the diester is isolated from the mixture (I)).

[0066] However, it is also possible that this catalyst is already at least partially removed from the mixture of process step (i) by the removal of the chemical compound split off during the condensation in process step (i). This means that the catalyst may be present only partially (relative to the amount used in process step (i)) or no longer at all in the mixture (I). However, as already explained above, the at least one catalyst used in process step (i) is preferably present at least partially in the mixture (I).

[0067] The at least one catalyst is used in process step (i) preferably in amounts of 1 to 1000 ppm, preferably 2 to 500 ppm, particularly preferably 5 to 50 ppm, very particularly preferably 10 to 30 ppm, based on the sum of the weight of dicarboxylic acid and diaryl carbonate. If several dicarboxylic acids are present, the information refers to all dicarboxylic acids present. The same applies to the diaryl carbonate. In the context of the present invention, ppb and ppm are to be understood as parts by weight, unless otherwise stated. In another embodiment, the process according to the invention is characterized in that the reaction in process step (i) is carried out in the presence of at least one first catalyst and optionally a second catalyst, and the condensation in process step (iii) is carried out at least in the presence of the second catalyst and optionally in the presence of the first catalyst.It is preferred that the first catalyst is at least one tertiary nitrogen base. These are particularly preferably the catalysts already described in more detail above. The second catalyst is preferably at least one basic alkali metal salt, alkaline earth metal salt, and / or a phosphonium or ammonium catalyst. The proportion of alkali metal cations or alkaline earth metal cations in process step (iii) is preferably 0.00001 to 0.0050 wt. %, based on all components used in process steps (i) to (iii).

[0068] The second catalyst is also preferably at least one phosphonium or ammonium catalyst. Most preferably, the second catalyst is a mixture of a basic alkali metal salt or alkaline earth metal salt and a phosphonium or ammonium catalyst. Phosphonium catalysts of formula (K1) or ammonium catalysts of formula (K2) are particularly suitable: where Ra, Rb, Rc and Rd can each be the same or different C1-C10 alkyls, C6-C14 aryls, C7-C15 arylalkyls or C5-C6 cycloalkyls, preferably methyl or C6-C14 aryls, particularly preferably methyl or phenyl, and X- can be an anion such as hydroxide, sulfate, boronate, in particular tetraphenylboronate, hydrogen sulfate, hydrogen carbonate, carbonate, acetate or a halide, preferably chloride, boronate or acetate or an alkylate or arylate of the formula -OR, where R can be a C6-C14 aryl, C7-C15 arylalkyl or C5-C6 cycloalkyl, preferably phenyl.

[0069] Particularly preferred catalysts are tetraphenylphosphonium chloride, tetrabutylphosphonium acetate, tetraphenylphosphonium tetraphenylboranate,

[0070] Tetraphenylphosphonium hydroxide and tetraphenylphosphonium phenolate; tetraphenylphosphonium phenolate is particularly preferred. Tetrabutylphosphonium acetate is also preferred.

[0071] Other particularly preferred catalysts are tetramethylammonium hydroxide, tetramethylammonium acetate, tetramethylammonium fluoride,

[0072] Tetramethylammonium tetraphenylboranate, dimethyldiphenylammonium hydroxide,

[0073] Tetraethylammonium hydroxide, cetyltrimethylammonium tetraphenylboranate and cetyltrimethylammonium phenoxide.

[0074] As stated above, it is also preferred that the second catalyst be a basic alkali metal salt or alkaline earth metal salt. It is particularly preferred that the second catalyst be selected from the group consisting of inorganic or organic alkali metal salts and inorganic or organic alkaline earth metal salts. Furthermore, the alkali metal cations present in process step (iii) are lithium cations, potassium cations, sodium cations, cesium cations, and mixtures thereof.

[0075] The second catalyst used is the organic or inorganic alkali or alkaline earth metal salt, preferably of a weak acid (pKa between 3 and 7 at 25 °C). Suitable weak acids include, 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-dimethylpropanoic acid, 2,2-dimethylpropanoic acid, 2,2-dimethylbutanoic acid, and 2-ethylhexanoic acid. It is also possible to use the organic or inorganic alkali or alkaline earth salt of a strong acid such as hydrochloric acid.

[0076] Suitable organic and inorganic salts are or are 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, dipotassium, and dilithium salts of BPA. Furthermore, 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 corresponding oleates can be used. Furthermore, corresponding salts of phenols, in particular phenol, can be used. These salts can be used individually or in mixtures.

[0077] The second catalyst is preferably selected from the group consisting of sodium hydroxide, lithium hydroxide, sodium phenolate, lithium phenolate, sodium benzoate, lithium benzoate, lithium chloride, lithium acetylacetonate, and cesium carbonate, as well as mixtures of these substances. Particular preference is given to using sodium phenolate, lithium phenolate, sodium hydroxide, lithium hydroxide, sodium benzoate, lithium benzoate, lithium chloride, and / or lithium acetylacetonate. Lithium chloride is preferably used as an aqueous solution, for example, in the form of a 15% solution.

[0078] These catalysts are preferably used in amounts of 10' 2 up to 10' 8 Mol, preferably 10' 2 up to 10' 6Mol, based on 1 mol of the components used in process step (iii). The amount of the basic alkali metal salt or alkaline earth metal salt can be used in the range from 0.01 to 20 ppm, preferably 0.05 to 15 ppm, and particularly preferably 0.1 to 10 ppm.

[0079] Thus, in this embodiment, a first catalyst and optionally a second catalyst are present in process step (i). Preferably, a first catalyst and a second catalyst are present in process step (i). It is not absolutely necessary for both catalysts to be catalytically active for the reaction carried out in process step (i). It is also possible that the second catalyst, in particular, is essentially only required in process step (iii) or is needed for its catalytic effect. Nevertheless, it may already be present in process step (i).

[0080] It is also preferred that at least one first catalyst is present in process step (i), optionally at least one second catalyst is added in process step (ii), and at least one second catalyst is present in process step (iii). It is apparent that the at least one first catalyst is different from the at least one second catalyst. It is also apparent that the at least one second catalyst is present in process step (iii) if it was added in process step (ii). Or, if process step (ii) is not carried out, the at least one second catalyst is added in process step (iii). Thus, it is also present in process step (iii). It is also preferred that the at least one first catalyst is also present in process step (ii), if this is carried out, and / or in process step (iii).Here too, it is not absolutely necessary that the at least one first catalyst is catalytically active for the reaction carried out in process step (ii) and / or process step (iii).

[0081] In process step (i) according to the invention, gas evolution is observed. This gas evolution arises from carbon dioxide formed and subsequently escaping. This carbon dioxide is the chemical compound split off during the condensation in process step (i). The carbon dioxide can be removed under atmospheric pressure or by applying a vacuum. Preferably, the temperature in process step (i) is initially increased. More preferably, the temperature in process step (i) is increased to 150°C to 200°C. Likewise preferred is a gradual increase in the temperature to 215-250°C, especially preferably 215-240°C. This allows the conversion of the condensation to be further increased.

[0082] In particular, it is preferred that the condensation reaction in process step (i) is at least 70%, particularly preferably at least 80%, furthermore preferably at least 90%, very particularly preferably at least 95% complete before process step (ii) or, if process step (ii) is not present, process step (iii) is started. From an economic point of view, it is expedient to achieve the highest possible conversion before starting the next process step. At the same time, it may be advantageous to start process step (ii) or (iii) at a somewhat earlier stage. The conversion can be determined by methods known to the person skilled in the art. For example, the reaction conversion could be deduced from the amount of carbon dioxide formed. The amount of carbon dioxide formed can advantageously be measured, for example, using a mass flow meter.

[0083] Alternatively, the conversion can also be determined by measuring the concentration of the carboxylic acid groups present. It is preferred that in process step (i), no more than 30%, particularly preferably no more than 20%, further preferably no more than 10%, most preferably no more than 5% of the originally used dicarboxylic acid is still present before process step (ii) or, if process step (ii) is not present, process step (iii) is commenced.

[0084] However, according to the invention, this also means that the reaction of all dicarboxylic acids present with the stoichiometrically corresponding diaryl carbonates need not have been completed before process step (ii) or (iii) is initiated. However, according to the invention, process step (i) is preferably carried out until a significant decline in gas formation can be observed, and only then is process step (ii) or (iii) initiated.

[0085] According to the invention, it has been found that the reaction time required to achieve the desired conversion, preferably the conversion described above, of the condensation reaction in process step (i) can be shortened by the process according to the invention. The shortening preferably relates to a comparison with a reaction in the classic owe-pot process, in which all structural units constituting the subsequent polymer (in particular also the 1,4:3,6-dianhydrohexitol) are present. It has also been found that the catalyst concentration in process step (i) according to the invention can be reduced compared to the two-stage process of the prior art. Preferably, the same, particularly preferably better, polymer properties (in particular color and / or molecular weight) are achieved.In addition, the process according to the invention has the advantage of one reaction step less (no isolation and / or purification of the mixture (I)), whereby the process according to the invention is overall more ecologically and economically advantageous.

[0086] Process step (i) provides a mixture (I). This mixture (I) contains the reaction product of the at least one dicarboxylic acid and the at least one diaryl carbonate. This can be a diaryl ester of the dicarboxylic acid. Depending on the conversion of the condensation reaction in process step (i), the mixture (I) can also at least partially contain free dicarboxylic acid and / or monoaryl ester of the dicarboxylic acid. In addition, the mixture (I) can still contain all or part of the catalyst used in process step (i). It is also possible that the temperatures used in process step (i) and / or the escaping gas have also removed the catalyst. In this case, it is not present in the mixture (I).However, it is also possible that in process step (i) the compounds released due to the temperatures used, with the exception of carbon dioxide, are recondensed and then optionally returned to the mixture of process step (i) and / or mixture (I). In particular, when diphenyl carbonate is used as diaryl carbonate, corresponding evaporation can occur in process step (i). Therefore, from an ecological and / or economic point of view, it can be advantageous to return the evaporated starting substances to process step (i). Furthermore, in process step (i), the chemical compound split off during condensation is removed. Such removal can be complete, essentially complete, or only partial.The skilled person is aware that the removal of this cleaved chemical compound can influence the equilibrium of the chemical reaction in process step (i). They can therefore choose the optimal procedure for the respective process. In some cases, the process in process step (i) can automatically result in the removal of this chemical compound cleaved during condensation, for example, through temperature control, gas evolution, and / or vacuum application.

[0087] It is particularly preferred that, in process step (i) according to the invention, 2.01 to 2.5, particularly preferably 2.05 to 2.2, moles of diaryl carbonate are used per 1 mole of the at least one dicarboxylic acid, and that further diaryl carbonate is added in process step (iii). Thus, in process step (i), a slight stoichiometric excess of the dicarboxylic acid is preferably used. It is also possible to add all the diaryl carbonate required for the reaction (i.e., required for process steps (i) and (iii)) in process step (i). In this case, however, side reactions such as increased Fries rearrangements, etc., may occur.

[0088] Preferably, a total ratio of diaryl carbonate to the sum of the dicarboxylic acid(s) used and the diol(s) used (including the 1,4:3,6-dianhydrohexitol) of approximately 0.98 to 1.02:1.02 to 0.98 is used. It will be apparent to those skilled in the art that the amount of diaryl carbonate used in process step (i) may also depend on the amount of dicarboxylic acid that is subsequently condensed into the polyester carbonate. This is particularly the case if additional diaryl carbonate is added in process step (iii).

[0089] Furthermore, the process step (i) according to the invention preferably comprises at least one, particularly preferably all of the following steps (ia) to (ic):

[0090] (ia) Melting all components present in process step (i), i.e., at least the at least one dicarboxylic acid and the at least one diaryl carbonate, in the presence of the at least one catalyst. This is preferably carried out under a protective gas atmosphere, preferably under nitrogen and / or argon. Step (ia) is preferably carried out in the absence of a solvent. The term "solvent" in this context is known to the person skilled in the art. According to the invention, the term "solvent" is preferably understood to mean a compound that does not enter into a chemical reaction in any of the process steps (i), (ii), and / or (iii). Excluded are those compounds that are formed by the reaction (for example, phenol, when diphenyl carbonate is used as the at least one diaryl carbonate). Of course, it cannot be ruled out that the starting compounds contain traces of solvents. This case is preferably encompassed according to the invention.However, according to the invention, an active step of adding such a solvent is preferably avoided.

[0091] (ib) Heating the mixture, preferably the melt obtained from step (ia). Steps (ia) and (ib) may also overlap, since heating may also be necessary to produce a melt in step (ia). Heating is preferably initially carried out to 150°C to 180°C.

[0092] (ic) Reaction of the mixture, preferably the mixture obtained from step (ib), with introduction of mixing energy, preferably by stirring. Here, too, step (ic) can overlap with step (ib), since the reaction of the mixture can be initiated by heating itself. Preferably, the melt has already been heated to temperatures between 150 and 180 °C under atmospheric pressure by step (ib). Depending on the catalyst selected, the temperature can be left in the range 160-200 °C. Alternatively, the temperature in step (ic) is gradually increased - depending on the observed reactivity - to 200 °C-300 °C, preferably 210-260 °C, particularly preferably 215-240 °C. The reactivity can be estimated from the gas evolution in a manner known to the person skilled in the art. In principle, higher temperatures are also possible in this step, but side reactions (e.g., discoloration) can occur at higher temperatures. Therefore, higher temperatures are less preferred.Process step (ic) is preferably carried out under atmospheric pressure. Stirring is continued until gas evolution essentially stops. The reaction time of this process step can be influenced by temperature control. According to the invention, it is possible that under these conditions, the aryl alcohol formed by the reaction of the at least one carboxylic acid with the at least one diaryl carbonate (for example, phenol when using diphenyl carbonate) is already partially removed (see above).

[0093] The reaction time in step (ic) depends on the amount of feedstock, the temperature profile used, and possibly also the stirring conditions (gas and / or surface exchange). The reaction time of step (ic) is preferably between 0.5 h and 24 h, preferably between 0.75 h and 5 h, and particularly preferably between 1 h and 3 h. It is preferable to select the reaction time such that gas evolution has substantially subsided / the reaction is substantially complete, or until the desired conversion is achieved (see above). Process step (i) can be carried out both batchwise and continuously. Due to the reaction time, it may be advantageous to carry out process step (i) batchwise. Therefore, it is preferred that process step (i) be carried out batchwise. All reactors familiar to the person skilled in the art are suitable for this purpose.If the process is carried out continuously, process step (i) could, for example, be carried out in a tubular reactor. If the process is carried out batchwise, the use of a stirred tank is particularly suitable. No pronounced increase in viscosity is observed during process step (i) and / or the mixture (I), so stirrers commonly known to those skilled in the art can be used. Furthermore, it is preferred that a reflux column be attached to such a stirred tank in order to condense any evaporated starting substances and / or reaction products and recycle them to process step (i) (see above).

[0094] According to the invention, process step (i) is preferably carried out in the absence of a 1,4:3,6-dianhydrohexitol. Particularly preferably, all 1,4:3,6-dianhydrohexitols required to synthesize the polyester carbonate are only added in process step (iii). It is preferred that mixture (I) does not comprise any 1,4:3,6-dianhydrohexitol and / or any reaction product of a 1,4:3,6-dianhydrohexitol.

[0095] According to the invention, it has surprisingly been found that the mixture (I) from process step (i) can be used in process step (ii) or (iii) without further purification. In this respect, the formulation “mixture (I) or (II) obtained directly from process step (i) or (ii)” is to be understood to mean that, in particular, no purification and / or isolation of the desired target product takes place. With regard to process step (i), this means, in particular, that the resulting diaryl ester of the dicarboxylic acid is present in the mixture (I) but is not isolated from it. Preferably, the mixture (I) comprises, in addition to the resulting diaryl ester, at least the first catalyst.

[0096] The process according to the invention optionally comprises a process step (ii), which, if present, is carried out after process step (i) and before process step (iii). In this process step (ii), at least one diol is contacted with the mixture (I) obtained directly from process step (i), or in this process step (ii), at least one diol is added to the mixture (I) obtained directly from process step (i), and at least a partial condensation of the compounds present in process step (ii) is carried out with removal of the chemical compound split off during the condensation to provide a mixture (II). Process step (ii) is carried out, in particular, with the aim of condensing the at least one diol with a compound of the mixture (I), in particular with the diaryl ester of the dicarboxylic acid of the mixture (I).

[0097] According to the invention, it is preferred that the mixture (I) no longer contains virtually any diaryl carbonate or aryl alcohol formed by process step (i) when process step (ii) is carried out. However, process step (ii) can also be carried out in the presence of the diaryl carbonate and / or aryl alcohol remaining from process step (i). Particularly preferably, the at least one catalyst remaining from process step (i) is still present in process step (ii).

[0098] It is preferred that the diol in process step (ii) is aliphatic or cycloaliphatic.

[0099] It is particularly preferred that the diol in process step (ii) is selected from the group consisting of 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2-bis(4-hydroxycyclohexyl)propane, tetrahydro-2,5-furandimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, cyclobutane-1,1-diyldimethanol, and 8-(hydroxymethyl)-3-tricyclo[5.2.1,02,6]decanyl]methanol, 2-butyl-2-ethyl-1,3-propanediol, 2-(2-hydroxyethoxy)ethanol, 2,2,4-trimethyl-l,3-pentanediol, 2,2-dimethylpropane-l,3-diol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,4:3,6-dianhydrohexitol and a compound of formula (4),

[0100] HO— (CH2) r — R 3 -(CH2) S — OH where each r and each s independently represents a number between 0 and 4 and each R 3independently represents a structure of the formulas (R3A), (R3B), (R3C) and (R3D) where a is 0 or 1, where the positions marked with in formulas (R3A) to (R3D) are the positions where the (CH2) shown in formula (4) r -group or (CH2)s-group. Preferably, the diol in process step (ii) is not 1,4:3,6-dianhydrohexitol. Furthermore, the diol in process step (ii) is preferably a diol with primary alcohol groups. Particularly preferably, the diol in process step (ii) is the above-mentioned diols which have primary alcohol groups. Thus, in particular, 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1,4:3,6-dianhydrohexitol should be deleted from the above list.

[0101] Preferably, in formula (4), each r and each s independently represents a number between 0 and 2, most preferably 0 or 1, and each R1 independently of each other for a structure of the formulas (RIA). In particular, it is preferred that r and s in formula (4) are 1 and R 1 represents the structure of formula (RIA). Formula (4) is particularly preferred: TCD-dimethanol (also referred to as TCD-alcohol, tricyclodecanedimethanol, or [8-(hydroxymethyl)-3-tricyclo[5.2.1.02,6]decanyl]methanol). TCD-dimethanol is generally present as a mixture of isomers. Up to 32 isomers are possible. Depending on the reaction conditions of the polymerization, the initial number and / or types of isomers in the monomer can also change in the resulting polymer.

[0102] Furthermore, the invention does not rule out the presence of aromatic diols in process step (ii). However, these are preferably present only in small proportions. Particular preference is given to additionally containing up to 20 mol%, further preferably up to 10 mol%, and very particularly preferably up to 5 mol% of an aromatic diol compound in process step (ii), based on the total amount of diol compound used. In these cases, the invention still preferably refers to an aliphatic polyester carbonate. However, it is particularly preferred not to use an aromatic diol compound in process step (ii). As a rule, aromatic compounds in polyester carbonates reduce their UV stability and weather resistance. This is particularly disadvantageous for outdoor applications. In addition, aromatic components in a polyester carbonate reduce the surface hardness of molded articles produced therefrom, which mayleading to the need for painting.

[0103] These additional aromatic diol compounds are preferably selected from the group consisting of bisphenol A, l,l-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-dihydroxybiphenyl (DOD), 4,4'-dihydroxybiphenyl ether (DOD ether), bisphenol B, bisphenol M, the bisphenols (I) to (III) where in these formulas (I) to (III) R' each represents C1-C4-alkyl, aralkyl or aryl, preferably methyl or phenyl, most preferably methyl.

[0104] Preferably, at least one further (second) catalyst is added in process step (ii). This (second) catalyst has already been described in more detail above.

[0105] It is preferred that the chemical compound(s) eliminated during the at least partial condensation in process step (ii) is / are removed by means of a vacuum. Accordingly, it is preferred that the process according to the invention is characterized in that, during the condensation in process step (ii), the volatile constituents which have a boiling point below that of the diester formed in process step (i), the diol and / or the compound formed in process step (ii) are separated off, if appropriate with a stepwise reduction in pressure. A stepwise separation is preferably chosen if different volatile constituents are separated off. A stepwise separation is likewise preferably chosen in order to ensure the most complete possible separation of the volatile constituent(s). The volatile constituents are the chemical compound(s) eliminated during the condensation.Compounds. This is preferably phenol.

[0106] A gradual reduction in pressure can be achieved, for example, by lowering the pressure as soon as the head temperature drops to ensure continuous removal of the chemical compound released during condensation.

[0107] The separation of the condensation product in process step (ii) preferably takes place at temperatures of 180°C to 320°C, preferably 190°C to 280°C, more preferably 195°C to 260°C, and especially preferably 200°C to 250°C. Furthermore, the vacuum during the separation is preferably 500 mbar to 0.01 mbar. In particular, it is preferred that the separation be carried out stepwise by reducing the vacuum. Most preferably, the vacuum in the final stage is 10 mbar to 0.01 mbar.

[0108] Process step (ii) allows the construction of a polyester carbonate with a specific structure. It was extremely surprising that, although the construction is possible sequentially and thus one after the other, the individual intermediate stages do not have to be isolated or separated. It is clear to those skilled in the art that the diester formed in process step (i) transesterifies with the diol of the optional process step (ii). This can lead to the formation of an oligoester block. The molecular weight of this oligoester block can be influenced by the temperature and / or vacuum control. This oligoester block is preferably a trimer of the at least one diol, which is 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.However, a trimer can also be formed, which, for example, comprises a centrally located diol which is linked to two dicarboxylic acids via two ester groups (where the end groups of the two dicarboxylic acids are usually esterified with an aryl group). Such a building block is very reactive due to the terminal aryl groups present. This trimer can be regarded as the simplest oligoester building block. Such a building block can then be condensed with 1,4:3,6-dianhydrohexitol and diaryl carbonate in process step (iii) to form the desired polyester carbonate.

[0109] Such an oligoester building block particularly preferably incorporates into the polyester carbonate via the acid or aryl ester group and not via an alcoholic OH group. However, those skilled in the art are aware that terminal OH groups may also be present to a small extent as a result of the preparation. The oligoester is particularly preferably a trimer of 1,4-cyclohexanedimethanol and 1,4-cyclohexanedicarboxylic acid or of 1,4-cyclohexanedimethanol and 1,4-cyclohexanedicarboxylic acid and terephthalic acid. The oligoester is also preferably a trimer of TCD-dimethanol and dimer fatty acid or of TCD-dimethanol and dimer fatty acid and terephthalic acid.

[0110] This process offers the particular advantage that differences in reactivity between different monomers can be compensated and / or circumvented. It is also advantageous that the targeted formation of ester groups with a diol is favored over carbonate groups of the same diol in the resulting polyester carbonate. This can significantly influence the resulting properties of the polyester carbonate. Furthermore, it is advantageous that this process allows the formation of ester groups with primary alcohols. It has been found that such ester groups are, in principle, particularly stable in process step (iii), in particular more stable than ester groups from diols with secondary alcohol groups. An exception are secondary alcohols that cannot be eliminated, such as tetramethylcyclobutanediol.Through such a targeted structure of the polyester carbonate, particularly transesterification-stable bonds can be introduced, which can positively influence the property profile.

[0111] It is preferred that process step (ii) be carried out in the same reactor as process step (i). Since no significant increase in viscosity is expected in process step (ii) either, this reactor is therefore suitable for carrying out process step (ii) as well. Of course, process step (ii) can also be carried out in the reactor in which process step (iii) is carried out later. Likewise, process step (ii) can be carried out in a separate reactor in which only process step (ii) is carried out.

[0112] The process according to the invention further comprises a process step (iii) in which at least one 1,4:3,6-dianhydrohexitol and optionally further diaryl carbonate are added to the mixture (I) obtained directly from process step (i) or, if a process step (ii) was carried out, to the mixture (II) obtained directly from process step (ii), and condensed with removal of the chemical compound split off during the reaction. Process step (iii) is preferably carried out in the presence of a catalyst, particularly preferably at least one second catalyst. It has already been explained above that, according to the invention, a distinction is made between a first catalyst, which is present in process step (i), and a second catalyst, which is optionally added in process step (ii) and is present in process step (iii) or is added in process step (iii).In this respect, reference is made to the at least one second catalyst described above.

[0113] It is particularly preferred that, in process step (iii), in addition to the at least one 1,4:3,6-dianhydrohexitol, a further diol is brought into contact or added. The process according to the invention is preferably characterized in that, in process step (iii), at least one further diol is additionally brought into contact with the mixture (I) obtained directly from process step (i) or, if a process step (ii) was carried out, with the mixture (II) obtained directly from process step (ii). Likewise, the process according to the invention is preferably characterized in that, in process step (iii), at least one further diol is additionally added to the mixture (I) obtained directly from process step (i) or, if a process step (ii) was carried out, to the mixture (II) obtained directly from process step (ii).This further diol is preferably a diol as already described in relation to process step (ii). Most preferably, the at least one further diol is tricyclodecanedimethanol (sometimes also referred to as TCD-dimethanol).

[0114] Here too, it was surprisingly found according to the invention that the direct contacting or direct addition of the components of process step (iii) to the mixture (I) or (II) obtained from the previously carried out process step is possible without isolating and / or purifying the mixture (I) or (II). The person skilled in the art would assume that the by-products and / or decomposition products that have already formed by the time process step (iii) is carried out have negative effects on the resulting polyester carbonate, in particular with regard to the molecular weight buildup and / or the color. Because no further purification and / or isolation step is necessary, the process according to the invention is particularly ecological and economical.

[0115] According to the invention, at least one 1,4:3,6-dianhydrohexitol is used in process step (iii). As is known to the person skilled in the art, 1,4:3,6-dianhydrohexitols are generally selected from the group consisting of isomannide, isoidide, and isosorbide. This can be a bio-based structural element, which entails all the advantages of a bio-based monomer and the resulting polymer (e.g., better sustainability, as it is obtainable from renewable raw materials). The process according to the invention is particularly preferably characterized in that the at least one 1,4:3,6-dianhydrohexitol is isosorbide. It is particularly advantageous if the at least one 1,4:3,6-dianhydrohexitol is dried before being added in process step (iii). Such drying can be carried out in a manner known to the person skilled in the art. In particular, dried 1,4:3,6-dianhydrohexitol leads to better control over the course of process step (iii).

[0116] Likewise, in process step (iii) according to the invention, further diaryl carbonate can optionally be brought into contact or added. This can be at least one diaryl carbonate. The diaryl carbonate that is optionally brought into contact or added in process step (iii) can be the same as or different from the at least one diaryl carbonate that is optionally brought into contact or added in process step (i). Preferably, the diaryl carbonate that is optionally brought into contact or added in process step (iii) is the same as the at least one diaryl carbonate that is optionally brought into contact or added in process step (i).

[0117] The contacting or addition of another diaryl carbonate in process step (iii) can preferably be used specifically to reduce the OH end group content of the resulting polyester carbonate. Such a procedure is described, for example, in JP2010077398 A.

[0118] The diaryl carbonate, which is optionally brought into contact or added in process step (iii), is preferably selected from a compound of formula (5), as explained in more detail above. The preferences and combinations of preferences explained above also apply in particular. The diaryl carbonate, which is optionally brought into contact or added in process step (iii), is particularly preferably diphenyl carbonate.

[0119] It is preferred that, in process step (iii), 0.75 to 1.00, particularly preferably 0.85 to 0.95, mol of diaryl carbonate are used per 2 mol of the at least one 1,4:3,6-dianhydrohexitol. If further diol is used in process step (iii), the moles of diaryl carbonate are based on all moles of OH-functional compounds present (i.e., 1,4:3,6-dianhydrohexitol plus further diol). This amount of diaryl carbonate in process step (iii) is particularly preferred if, in process step (i), 2.01 to 2.5, particularly preferably 2.05 to 2.2, mol of diaryl carbonate are used per 1 mol of the at least one dicarboxylic acid, and further diaryl carbonate is added in process step (ii). Such a process procedure is preferred over the process procedure in which all diaryl carbonate required for the entire process according to the invention is used in process step (i).The loss of diaryl carbonate in process step (i) and possibly (ii) as well as the formation of by-products can thus be minimized.

[0120] As already explained above, the amount of diaryl carbonate used in process step (iii) depends on the amount already used in process step (i). This amount, in turn, depends on the ratio of the ester groups (determined by the use of the dicarboxylic acid) and carbonate groups (determined by the use of diols, including 1,4:3,6-dianhydrohexitol) present in the polyester carbonate to be produced.Preferably, in process step (i) at least twice the molar ratio, preferably 2.1 times, of diaryl carbonate is used in relation to the dicarboxylic acid, and in process step (iii) the molar residual amount of diaryl carbonate minus the excess used in process step (i), where the molar residual amount of diaryl carbonate is the molar amount resulting from the molar ratio of diaryl carbonate to the sum of dicarboxylic acid and 1,4:3,6-dianhydrohexitol (and optionally further dicarboxylic acid and / or further diol) of 1:1 minus the molar amount of diaryl carbonate used in process step (i). It will be apparent to those skilled in the art that they can also deviate from the above-mentioned ratio. For example, by using a proportionally higher amount of diaryl carbonate, the molecular weight can be controlled, in particular limited, and / or the content of phenolic OH groups in the polymer can be reduced.If, on the other hand, the content of phenolic OH groups is to be as high as possible, the proportional amount of diaryl carbonate can be reduced. Likewise, it can also be taken into account if a diol is partially removed during the reaction (for example, due to the reaction conditions under which vacuum is applied) and / or degraded (e.g., by thermal decomposition). In this case, too, a smaller proportion of diaryl carbonate could be used. In process step (iii), the mixture (I) obtained from process step (i) or the mixture (II) obtained from process step (ii) is condensed at least with removal of the chemical compound split off during the condensation. The condensation in process step (iii) is preferably understood as a further condensation.According to the invention, the term "further" condensation means that at least some condensation has already taken place in process step (i). This preferably involves the reaction of the at least one dicarboxylic acid with the at least one diaryl carbonate, with elimination of an aryl alcohol. However, further condensation to form oligomers may also have already taken place (see process step (ii)).

[0121] If only the at least one first catalyst was used in process step (i), the at least one second catalyst is added in process step (ii) and / or in process step (iii).

[0122] In a preferred embodiment, the first catalyst and the second catalyst are present in process step (i).

[0123] It is also possible to use a portion of the first catalyst and / or a portion of the second catalyst in process step (i) and then the respective remainder in process step (iii).

[0124] It is preferred that the chemical compound(s) eliminated during the condensation be removed by means of a vacuum in process step (iii). Accordingly, it is preferred that the process according to the invention is characterized in that the chemical compound(s) eliminated during the condensation are separated in process step (iii) under a stepwise reduction of the pressure. A stepwise separation is preferably selected if different volatile constituents are to be separated. A stepwise separation is also preferably selected in order to ensure the most complete possible separation of the volatile constituent(s). The volatile constituents are the chemical compound(s) eliminated during the condensation. This is in particular the aryl alcohol formed, particularly preferably phenol.

[0125] A gradual reduction in pressure can be achieved, for example, by lowering the pressure as soon as the head temperature drops to ensure continuous removal of the chemical compound released during condensation. Once a pressure of 1 mbar, preferably < 1 mbar, is reached, condensation continues until the desired viscosity is achieved. This can be achieved, for example, by torque control, i.e., the polycondensation is terminated when the desired stirrer torque is reached.

[0126] The separation of the condensation product in process step (iii) preferably takes place at temperatures of 180°C to 320°C, preferably 190°C to 280°C, more preferably 195°C to 260°C, and especially preferably 200°C to 250°C. Furthermore, the vacuum during the separation is preferably 500 mbar to 0.01 mbar. In particular, it is preferred that the separation be carried out stepwise by reducing the vacuum. Most preferably, the vacuum in the final stage is 10 mbar to 0.01 mbar.

[0127] Process step (iii) can be carried out batchwise or continuously. Process step (iii) is preferably carried out continuously. During process step (iii), viscosity increases. Above a certain viscosity / molecular weight, condensation in a stirred tank may no longer be efficient, as surface renewal decreases and the removal of low-molecular-weight condensation products (particularly phenol) is more difficult. Therefore, it is particularly useful to carry out process step (iii) in a process unit such as a high-viscosity reactor, disk or grid reactor, extruder, or thin-film evaporator. However, it is also possible to carry out process step (iii) in a stirred tank, possibly even the same stirred tank as in process step (i), provided it has suitable stirring tools.

[0128] It has also been surprisingly found that a further advantage of the process according to the invention is the improved utilization of the reactor volume. A relatively large volume fraction of the reactor is occupied by at least one diaryl carbonate in process step (i). At least a portion of the diaryl carbonate is removed during process step (i) by the reaction, inter alia, to form carbon dioxide. Furthermore, the resulting aryl alcohol, preferably phenol, is also at least partially removed in process step (i). This means that after completion of process step (i), the volume in the reactor of process step (i) is reduced by approximately 50%.If a conventional pot process is carried out, this volume is essentially lost for further condensation to polyester carbonate because it cannot be used (it is not replenished by adding another substance, since all substances are already present in the reactor from the start). However, in the sequential procedure according to the invention, it is possible to add the other reactants and additional diaryl carbonate required for the reaction after removal of the carbon dioxide in the first stage. This allows for more efficient use of the reactor volume, which increases the economic viability of the process. Thus, it is preferred that the entire process according to the invention be carried out in one reactor. This means that process step (i), optionally process step (ii), and process step (iii) are carried out in one reactor. According to the invention, a polyester carbonate is obtained after process step (iii).This may, if necessary, be subjected to further purification steps, such as granulation steps, etc. Such steps are known to the person skilled in the art.

[0129] The polyestercarbonate obtained by the process according to the invention preferably has a relative solution viscosity above 1.20, particularly preferably from 1.21 to 1.65, further preferably from 1.22 to 1.63, especially preferably from 1.23 to 1.62, and most preferably from 1.26 to 1.55. According to the present invention, the relative solution viscosity (r|rel; also referred to as eta rel) is preferably determined in dichloromethane at a concentration of 5 g / l at 25°C using an Ubbelohde viscometer. The determination of the relative solution viscosity using an Ubbelohde viscometer is known to those skilled in the art. According to the invention, this is preferably carried out according to DIN 51562-3; 1985-05. The flow times of the polyester carbonate to be measured through the Ubbelohde viscometer are measured in order to subsequently determine the viscosity difference between the polymer solution and its solvent.For this purpose, the Ubbelohde viscometer is first calibrated by measuring the pure solvents dichloromethane, trichloroethylene, and tetrachloroethylene (at least three measurements are always taken, and no more than nine). This is followed by the actual calibration with the solvent dichloromethane. The polymer sample is then weighed, dissolved in dichloromethane, and the flow time for this solution is determined three times. The mean of the flow times is corrected using the Hagenbach correction, and the relative solution viscosity is calculated.

[0130] This preferred relative solution viscosity ensures that the polyestercarbonates obtained by the process according to the invention have sufficient mechanical properties. "Sufficient" is understood here to mean that they exhibit mechanical properties comparable to those of conventional aromatic polycarbonates, in particular ductility in an unnotched impact test at room temperature. This preferably means that the resulting polyestercarbonate rods do not break in the Charpy or Izod impact test without a notch, or only break at very high energy absorption – particularly preferably, they exhibit NB (no brake).

[0131] It is apparent to those skilled in the art how the starting materials, in particular the dicarboxylic acid, the diaryl carbonate and the 1,4:3,6-dianhydrohexitol (and optionally further diols) are used in process steps (i) to (iii) to obtain a polyester carbonate of the desired composition. In particular, it is preferred that 8 mol% to 40 mol% of dicarboxylic acid, particularly preferably 15 to 35 mol% of dicarboxylic acid, based on the total molar amount of the dicarboxylic acid 1,4:3,6-dianhydrohexitol, are used in process step (i). It is likewise preferred that 60 to 92 mol%, particularly preferably 65 to 85 mol% of 1,4:3,6-dianhydrohexitol are used in process step (iii), based on the total molar amount of the dicarboxylic acid and the 1,4:3,6-dianhydrohexitol.

[0132] It is also preferred that in process step (i) 2 to 14 mol%, particularly preferably 3 to 12 mol%, very particularly preferably 3.5 to 7.5 mol% of at least one dicarboxylic acid, particularly preferably dimer fatty acid, are used, based on the total amount of dicarboxylic acids used, optionally further diols and 1,4:3,6-dianhydrohexitol. It is likewise preferred that in process step (ii) 4 to 25 mol%, particularly preferably 5 to 20 mol%, equally preferably 7 to 18 mol% and very particularly preferably 10 to 15 mol%, very particularly preferably 5 to 10 mol% or equally very particularly preferably 8 to 12 mol% of at least one further diol, particularly preferably TCD-dimethanol, are used, based on the total amount of dicarboxylic acids used, optionally further diols and 1,4:3,6-dianhydrohexitol.Alternatively, in process step (iii) 4 to 25 mol%, particularly preferably 5 to 20 mol%, likewise preferably 7 to 18 mol%, very particularly preferably 10 to 15 mol% or likewise very particularly preferably 8 to 12 mol% of at least one further diol, particularly preferably TCD-dimethanol, can be used, based on the total molar amount of dicarboxylic acids used, optionally further diols and 1,4:3,6-dianhydrohexitol. Furthermore, it is preferred that at least 55 mol%, particularly preferably at least 65 mol%, likewise preferably at least 75 mol% and very particularly preferably at least 80 mol% of the 1,4:3,6-dianhydrohexitol, particularly preferably isosorbide, are used, based on the total molar amount of dicarboxylic acids used, optionally further diols and 1,4:3,6-dianhydrohexitol.

[0133] Likewise, according to the invention, a polyester carbonate is provided, obtained by the process according to the invention, optionally in all preferred forms and / or combinations of preferred forms, wherein the process necessarily comprises process step (ii). As already explained above, this polyester carbonate has a specific structure because it was produced sequentially. Thus, the polyester carbonate comprises specific, targeted and controlled bonds of the monomers via ester groups and similarly targeted, controlled bonds via carbonate groups. This allows the property profile of the polyester carbonate according to the invention to be specifically influenced. It is particularly preferred that the polyester carbonate according to the invention and / or the polyester carbonate obtained by the process according to the invention is at least 50 mol%, more preferably at least 70 mol%, and most preferably at least 75 mol% bio-based.For the purposes of the present invention, the term "bio-based" means that the chemical compound in question is accessible, obtainable, and / or preferably is a renewable and / or regenerative raw material at the time of application. A renewable and / or regenerative raw material is preferably understood to mean a raw material that is regenerated by natural processes at a rate comparable to its degradation rate (see CEN / TS 16295:2012). The term is used in particular to distinguish it from raw materials made from fossil fuels, also known as petro-based. Whether a raw material is bio-based or petro-based can be determined by measuring carbon isotopes in the raw material, since the relative amounts of the carbon isotope C. 14are lower in fossil raw materials. This can be done, for example, according to ASTM D6866-18 (2018) or ISO16620-1 to -5 (2015) or DIN SPEC 91236 2011-07. According to the invention, the term "biobased" is preferably used for compounds that have a C 14 Isotope content of over 0.1 x 10' 12 , particularly preferably over 0.2 x 10' 12 , and most preferably above 0.3 x 10 12 In particular, isosorbide and dimer fatty acid are bio-based.

[0134] In a further aspect of the present invention, a molded article containing the polyester carbonate according to the invention is provided. The molded articles according to the invention can be produced, for example, by injection molding, extrusion, and blow molding. Another form of processing is the production of molded articles by deep drawing from previously produced sheets or films.

[0135] Examples

[0136] Materials used:

[0137] Cyclohexanedicarboxylic acid: 1,4-Cyclohexanedicarboxylic acid; CAS 1076-97-7 99%; Tokyo Chemical Industries, Japan, abbreviated as CHDA. According to elemental analysis, CHDA contained less than 1 ppm sodium.

[0138] Diphenyl carbonate: Diphenyl carbonate, 99.5%, CAS 102-09-0; Acros Organics, Geel, Belgium, abbreviated as DPC

[0139] 4-Dimethylaminopyridine: 4-(Dimethylaminopyridine; >98.0%; purum; CAS 1122-58-3; Sigma-Aldrich, Munich Germany, abbreviated as DMAP

[0140] Isosorbide: Isosorbide (CAS: 652-67-5), 99.8%, Polysorb PS A; Roquette Freres (62136 Lestrem, France); abbreviated as ISB

[0141] Lithium hydroxide monohydrate (CAS: 1310-66-3); >99.0%; Sigma-Aldrich

[0142] 1,4-Cyclohexanedimethanol: CAS: 105-08-8, Aldrich 99% (cis, trans isomer mixture; abbreviated as CHDM)

[0143] Terephthalic acid: (CAS: 100-21-0), 99+%, Acros Organics, Geel, Belgium

[0144] Isophthalic acid: (CAS: 121-91-5), 99%, Alfa Aesar, ThermoFisher (Kandel) GmbH, (76870 Kandel, Germany)

[0145] Tricyclodecanedimethanol: (CAS: 26896-48-0) ; mixture of isomers ; OQ Chemicals, 40789 Monheim, Germany (abbreviated as TCD-Dimethanol)

[0146] Dimer fatty acid: Pripol 1009 (CAS: 68783-41-5); Mn approx. 570 g / mol; hydrogenated, Croda, 41334 Nettetal, Germany (abbreviated as DFA)

[0147] Sodium 2-ethylhexanoate, 97%, CAS 19766-89-3; Sigma-Aldrich, Munich, Germany

[0148] Chlorobenzene: (CAS: 108-90-7), Sigma Aldrich, 99.8%

[0149] Analytical methods:

[0150] Solution viscosity: The relative solution viscosity (r|rel; also referred to as eta rel) was determined in dichloromethane at a concentration of 5 g / l at 25 °C using an Ubbelohde viscometer. The determination was carried out according to DIN 51562-3; 1985-05. The flow times of the polyester carbonate to be measured through the Ubbelohde viscometer are measured to subsequently determine the viscosity difference between the polymer solution and its solvent. For this purpose, the Ubbelohde viscometer is first calibrated by measuring the pure solvents dichloromethane, trichloroethylene, and tetrachloroethylene (at least three measurements are always taken, but no more than nine). This is followed by the actual calibration with the solvent dichloromethane. The polymer sample is then weighed, dissolved in dichloromethane, and the flow time for this solution is then determined three times.The mean value of the flow times is corrected using the Hagenbach correction and the relative solution viscosity is calculated.

[0151] Determination of the glass transition temperature:

[0152] The glass transition temperature was determined by differential scanning calorimetry (DSC) according to DIN EN ISO 11357-1:2009-10 and ISO 11357-2:2013-05 at a heating rate of 10 K / min under nitrogen with determination of the glass transition temperature (Tg) measured as the inflection point in the second heating process.

[0153] The color of the polyester carbonates was determined visually by the same person.

[0154] 13 C NMR spectroscopy: The measurements were performed on a Bruker Avance NEO 600 MHz NMR spectrometer. The measurements were performed in CDCl.

[0155] Production of the reactants:

[0156] Production of tetrabutylphosphonium acetate

[0157] 483.38 g of an aqueous tetrabutylphosphonum hydroxide solution (mass fraction: 40%) were placed in an Erlenmeyer flask. Approximately 40 mL (0.7 mol) of pure acetic acid were then added dropwise until a pH of approximately 6 was reached. The 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 for at least 12 h in a sealed vessel. The product was then filtered and concentrated to maximum at 80 °C and <0.2 mbar. Upon cooling in the gas-tight vessel, the product crystallized at approximately 40 °C. Color: light brown Example 1 (according to the invention; polyester carbonate from isosorbide and 1,4, cyclohexanedicarboxylic acid and 2-butyl-2-ethyl-l,3-propanediol; sequential one-pot)

[0158] 17.22 g (0.10 mol) of 1,4-cyclohexanedicarboxylic acid, 64.27 g (0.30 mol) of diphenyl carbonate and 0.0023 g (20 ppm) of DMAP as well as 30 pL of an aqueous lithium hydroxide solution [ß(LiOH) = 100 g / L] were placed in a flask with a short-path separator.

[0159] The mixture was freed from oxygen by fourfold evacuation and intersting with nitrogen, melted and heated to 160 °C at atmospheric pressure while stirring.

[0160] After the temperature was reached, it was checked whether carbon dioxide was produced (bubble counter).

[0161] As carbon dioxide evolution decreased, the temperature was gradually increased to 210 °C until CO2 evolution slowed and finally ceased. The increase in temperature also distilled off phenol.

[0162] The reaction mixture was then purged with nitrogen and cooled to ambient temperature. 26.83 g (0.1836 mol) of isosorbide and 3.27 g (0.02 mol) of 2-butyl-2-ethyl-1,3-propanediol were added to the reaction mixture.

[0163] The mixture was then freed of oxygen by evacuating it four times and inerting it with nitrogen. The temperature was gradually increased to 210 °C over a period of 20 minutes.

[0164] After a 10-minute hold at 210 °C, the temperature was increased to approximately 235 °C, during which time increasing amounts of phenol distilled off. As soon as no more distillate formed, the pressure was carefully reduced gradually over 45 minutes to <1 mbar to ensure the distillation was as continuous as possible. Condensation was continued at 0.1 to 0.5 mbar for approximately 10 minutes at low speed.

[0165] A slightly yellowish, transparent polymer was obtained. The solution viscosity is given in Table 1.

[0166] Example 2 (according to the invention, sequential one-pot, with higher catalyst content)

[0167] The example was carried out as in Example 1. Instead of 20 ppm, 100 ppm DMAP (0.011 g) was used. A yellowish polymer was obtained. The solution viscosity is given in Table 1.

[0168] Example 3 (comparison example one-pot)

[0169] 26.83 g (0.1836 mol) of isosorbide, 3.27 g (0.02 mol) of 2-butyl-2-ethyl-l,3-propanediol, 17.22 g (0.10 mol) of 1,4-cyclohexanedicarboxylic acid, 64.27 g (0.30 mol) of diphenyl carbonate, and 0.0023 g (20 ppm) of DMAP, as well as 30 pL of an aqueous lithium hydroxide solution [ß(LiOH) = 100 g / L] were placed in a flask with a short-path separator.

[0170] The mixture was freed of oxygen by evacuating four times and inerting with nitrogen. The mixture was melted and heated to 160 °C at atmospheric pressure while stirring. Carbon dioxide evolved continuously starting at approximately 140 °C. As gas evolution decreased, the temperature was gradually increased to 210 °C. After the CO2 evolution ceased, a clear, slightly yellowish solution was obtained.

[0171] The temperature was then increased to 235 °C, during which phenol distilled off. As soon as no more distillate formed, the pressure was carefully reduced gradually over 45 minutes to <1 mbar to ensure the distillation was as continuous as possible. Condensation was continued at 0.1 to 0.5 mbar for approximately 10 minutes at low speed.

[0172] A brown, transparent polymer was obtained. The solution viscosity is given in Table 1.

[0173] Example 4: according to the invention, sequential one-pot with CHDA, DFA and TCD-dimethanol)

[0174] 16.96 g (0.9850 mol) of 1,4-cyclohexanedicarboxylic acid, 44.99 g (0.21 mol) of diphenyl carbonate, 0.855 g of dimer fatty acid (0.0015 mol) and 0.0057 g (50 ppm) of DMAP were placed in a flask fitted with a short-path separator.

[0175] The mixture was freed from oxygen by fourfold evacuation and intersting with nitrogen, melted and heated to 160 °C at atmospheric pressure while stirring.

[0176] Once the temperature was reached, the evolution of carbon dioxide was monitored (bubble counter). As carbon dioxide evolution decreased, the temperature was gradually increased to 210 °C until CO2 evolution slowed and finally ceased. Phenol was also distilled off as a result of the temperature increase. The reaction mixture was then vented with nitrogen and cooled to ambient temperature. 25.34 g (0.1734 mol) of isosorbide, 6.01 g (0.0306 mol) of TCD alcohol, 19.28 g (0.09 mol) of DPC, and 20 μL of an aqueous lithium hydroxide solution [ß(LiOH)] were added. = 100 g / L] was added to the reaction mixture.

[0177] The mixture was then freed of oxygen by evacuating it four times and inerting it with nitrogen. The temperature was gradually increased to 210 °C over a period of 20 minutes.

[0178] After a 10-minute hold at 210 °C, the temperature was increased to approximately 235 °C, during which time increasing amounts of phenol distilled off. As soon as no more distillate formed, the pressure was carefully reduced gradually over 45 minutes to <1 mbar to ensure the distillation was as continuous as possible. Condensation was continued at 0.1 to 0.5 mbar for approximately 10 minutes at low speed.

[0179] A slightly yellowish transparent polymer was obtained. The solution viscosity was 1.271

[0180] Table 1:

[0181] * The person skilled in the art is aware that the absolute times of process step (i) can be influenced and optimized by the temperature control; at the same time, however, the person skilled in the art is aware that the differences in reaction times, for example, between Examples 1 and 2 and Comparative Example 3, are so great that an optimized process control that could equalize them is very unlikely.

[0182] Example 1 according to the invention shows that at very low catalyst concentrations (only one-fifth of the concentration used in Example 2), both relatively high molecular weights and very light-colored products can be produced. Higher catalyst concentrations significantly increase the molecular weight, although the color suffers slightly, although this is still within the tolerance range. In contrast, the comparative example shows that the color of the polymer in the one-pot synthesis (bow-pot synthesis) is significantly poorer. It is also disadvantageous that high molecular weights cannot be achieved at low catalyst contents. Furthermore, it can be seen that, with the inventive procedure and the same catalyst concentration, a significantly shorter reaction time is required for process step (i) than for the conventional bow-pot process (Example 1 compared to Example 3).

[0183] Example 5 (according to the invention - sequential construction of the polymer structure)

[0184] 6.89 g (0.04 mol) of 1,4-cyclohexanedicarboxylic acid, 6.65 g (0.04 mol) of terephthalic acid, 34.96 g (0.163 mol) of diphenyl carbonate, 0.027 g (250 ppm) of DMAP, and 30 pL of an aqueous lithium hydroxide solution [ß(LiOH) = 100 g / L] were placed in a flask with a short-path separator and dropping funnel.

[0185] The mixture was freed of oxygen by evacuating and venting with nitrogen four times. The mixture was melted and heated to 160 °C at atmospheric pressure while stirring. The mixture was stirred for 50 minutes at 160 °C, for 50 minutes at 175 °C, for 30 minutes at 190 °C, and for 50 minutes at 210 °C. Carbon dioxide evolved continuously.

[0186] Once gas evolution ceased and the solution had become clear, the pressure was reduced to approximately 10 mbar to remove phenol and excess diphenyl carbonate. The reaction mixture was then purged with nitrogen and cooled to 180 °C. 5.77 g (0.04 mol) of 1,4-cyclohexanedimethanol were added to the reaction mixture. The temperature was gradually increased again to 210 °C. The pressure was then reduced to approximately 250 mbar, with phenol continuously removed.

[0187] As soon as no more distillate formed, the mixture was purged with nitrogen, and 23.62 g (0.162 mol) of isosorbide and 25.71 g (0.12 mol) of diphenyl carbonate were placed in a dropping funnel. The mixture was melted with a hot air dryer and added dropwise to the mixture.

[0188] The temperature was gradually increased to 235 °C, and the pressure was carefully reduced step by step to approximately 1 mbar. The reaction mixture was stirred for 10 minutes at minimal pressure. The product was then removed. An intensely orange, transparent polymer with an eta rel. of 1.262 was obtained.

[0189] Example 6 (comparative example one-pot with unregulated polymer structure)

[0190] 20.66 g (0.12 mol) of 1,4-cyclohexanedicarboxylic acid and 70.15 g (0.48 mol) of isosorbide, 179.95 g (0.84 mol) of diphenyl carbonate, 17.31 g (0.12 mol) of 1,4-cyclohexanedimethanol, 19.94 g (0.12 mol) of terephthalic acid as well as 0.077 g of DMAP (4-dimethylaminopyridine; 250 ppm based on the starting materials) and 0.009 g of lithium hydroxide in the form of an aqueous solution (90 μl of an aqueous solution of Li OH (100.0 g / l)) were placed in a flask with a short-path separator.

[0191] The mixture was freed of oxygen by evacuating and venting with nitrogen four times. The mixture was melted and heated to 160 °C at atmospheric pressure while stirring.

[0192] The mixture was stirred for 20 minutes at 160 °C, for 20 minutes at 175 °C, for 15 minutes at 190 °C, and for 30 minutes at 210 °C. Carbon dioxide evolved continuously.

[0193] Once gas evolution ceased and the solution became clear, the temperature was increased to 225 °C so that phenol distilled off. As phenol distillation subsided, the temperature was increased to 235 °C and the pressure was slowly reduced to approximately 1 mbar over the course of an hour to maintain the distillation. The reaction mixture was stirred for 10 minutes at minimal pressure. The product was then removed. An orange-colored polymer with an eta rel. of 1.286 was obtained. The further results are shown in Table 2.

[0194] Table 2: As can be seen from Table 2, the polymer obtained after the sequential procedure lacks CHDM carbonate groups and thus exhibits a different structure. This is also reflected in the changed glass transition temperature.

[0195] Experiment 7 (according to the invention)

[0196] 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 placed in a flask fitted with a short-path separator. The mixture was freed of oxygen by four-fold evacuation and purging with nitrogen, melted, and heated to 160 °C at atmospheric pressure with stirring.

[0197] After the temperature was reached, it was checked whether carbon dioxide was produced (bubble counter).

[0198] As carbon dioxide evolution decreased, the temperature was gradually increased to 240 °C until CO2 evolution slowed and finally ceased. Phenol was also distilled off by increasing the temperature.

[0199] The reaction mixture was then vented with nitrogen and cooled to ambient temperature. 111.80 g (0.765 mol) of isosorbide, 17.67 g (0.09 mol) of tricyclodecanedimethanol, 157.15 g (0.7335 mol) of diphenyl carbonate, and 34 μL of an aqueous lithium hydroxide solution [ß(LiOH)] were added. = 100 g / L] was added to the reaction mixture.

[0200] The mixture was then freed of oxygen by evacuating it four times and inerting it with nitrogen. The temperature was gradually increased to 210 °C over a period of 20 minutes.

[0201] After a 10-minute hold at 210 °C, the temperature was increased to approximately 235 °C, during which time increasing amounts of phenol distilled off. As soon as no more distillate formed, the pressure was carefully reduced gradually over 45 minutes to <1 mbar to ensure the distillation was as continuous as possible. Condensation was continued at 0.1 to 0.5 mbar for approximately 10 minutes at low speed. A yellowish polymer with an eta rel. of 1.247 was obtained.

[0202] Experiment 8 (Preparation of the diphenyl ester of dimer fatty acid)

[0203] 142.50 g (0.250 mol) of dimer fatty acid (hydrogenated), 107.32 g (0.501 mol) of diphenyl carbonate, and 0.0025 g (100 ppm) of DMAP were placed in a flask fitted with a short-path separator. The mixture was freed of oxygen by four evacuations and purging with nitrogen, melted, and heated to 160 °C at atmospheric pressure with stirring.

[0204] Carbon dioxide began to evolve at approximately 140°C. As the flow rate decreased, the temperature was gradually increased to a maximum of 240°C. Phenol also distilled off as a result of the temperature increase. Once gas evolution ceased, the pressure was gradually reduced to approximately 1 mbar. The reaction continued until no more phenol evolved.

[0205] Once the orange-yellow product had cooled, it was poured out. The color of the product indicates that catalyst was still present.

[0206] Experiment 9 (according to the invention):

[0207] 118.37 g (0.810 mol) of isosorbide, 8.85 g (0.045 mol) of tricyclodecanedimethanol, 175.25 g (0.8181 mol) of diphenyl carbonate and 34 pL of an aqueous lithium hydroxide solution [ß(LiOH) = 100 g / L] into a 250 mL three-neck flask.

[0208] The mixture was freed from oxygen by fourfold evacuation and intersting with nitrogen, melted and heated to 160 °C at atmospheric pressure while stirring.

[0209] After the temperature was reached, 32.49 g (0.045 mol) of the diphenyl ester of the dimer fatty acid from experiment 8 were added completely using a dropping funnel.

[0210] After a 10-minute hold phase at 210 °C, the temperature was increased to approximately 235 °C, during which increasing amounts of phenol distilled off. As soon as no more distillate formed, the pressure was carefully reduced gradually over 45 minutes to <1 mbar to ensure the distillation was as continuous as possible. Condensation was continued at 0.1 to 0.5 mbar for approximately 10 minutes at low speed. A slightly yellowish polymer with an eta rel. of 1.281 was obtained.

[0211] Experiment 10 (according to the invention):

[0212] 32.49 g (0.045 mol) of dimer fatty acid diphenyl ester from Example 8, 111.80 g (0.765 mol) of isosorbide, 17.67 g (0.09 mol) of tricyclodecanedimethanol, 177.21 g (0.8272 mol) of diphenyl carbonate, 900 μL of an aqueous sodium (2-ethyl)hexanoate solution [β=0.5 g / L], and 150 μL of a tetrabutylphosphonium acetate solution in chlorobenzene (100 g / L) were placed in a flask equipped with a short-path separator. The mixture was freed of oxygen by four evacuations and inerting with nitrogen, melted, and heated to 160 °C at atmospheric pressure with stirring.

[0213] The temperature was gradually increased to 210 °C within 30 minutes.

[0214] The temperature was then raised to approximately 235 °C, during which increasing amounts of phenol distilled off. As soon as no more distillate formed, the pressure was carefully reduced gradually over 45 minutes to <1 mbar to ensure the distillation was as continuous as possible. Condensation was continued at 0.1 to 0.5 mbar for approximately 10 minutes at low speed. A slightly yellowish polymer with an eta rel. of 1.298 was obtained.

Claims

1. A process for producing a polyester carbonate by melt transesterification, comprising in this order (i) Condensation of 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 with removal of the chemical compound split off during the condensation to provide a mixture (I), optionally a process step (ii) comprising (ii) bringing at least one diol into contact with the mixture (I) obtained directly from process step (i), and at least partially condensing the compounds present in process step (ii) with removal of the chemical compound split off during the condensation to provide a mixture (II), (iii) bringing into contact at least one 1,4:3,6-dianhydrohexitol and optionally further diaryl carbonate with the mixture (I) obtained directly from process step (i) or, if a process step (ii) has been carried out, with the mixture (II) obtained directly from process step (ii) and condensing to remove the chemical compound split off during the reaction.

2. Process according to claim 1, characterized in that the condensation reaction in process step (i) is at least 70% complete before process step (ii) or, if process step (ii) is not present, process step (iii) is started.

3. The method according to claim 1 or 2, characterized in that the at least one dicarboxylic acid is selected from the group consisting of the compounds represented by formula (1), (2) and (3), furandicarboxylic acid, naphthalenedicarboxylic acid, phthalic acid, isophthalic acid and terephthalic acid, where where in formulas (1) and (2) B each independently represents a CH2 group or a heteroatom selected from the group consisting of O and S, preferably a CH2 group or an oxygen atom, Ri each independently represents 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, particularly preferably a single bond, and n is a number between 0 and 3, preferably 0 or 1, and where in formula (3) each R 2independently represent an aliphatic group having 16 to 44 carbon atoms, which may contain one or more double bonds.

4. Method according to claim 3, characterized in that R 2 in formula (3) is represented by the following formula (R2A) with (R2A), wherein Y represents a bridging structure selected from the group consisting of an alkylene group having 1 to 4 carbon atoms, an alkylidene group having 1 to 4 carbon atoms, and a cycloalkylene group having 4 to 12 carbon atoms, wherein the cycloalkylene group optionally contains one or more double bonds and / or is optionally condensed to one or more further cycloalkylene groups, wherein the one or more further cycloalkylene groups optionally each have one or more double bonds, wherein the R adjacent to the bridging structure 11-groups are bonded to any position of the bridging structure and where each R 11 independently of one another represents an alkylene group having 1 to 12 carbon atoms or an alkylidene group having 1 to 12 carbon atoms, with the proviso that the structure of formula (R2A) comprises 16 to 44 carbon atoms and wherein the positions marked with , in formula (R2A) are the positions at which the (C=O) groups shown in formula (3) are located.

5. Process according to claim 4, characterized in that the formula (R2A) is represented by one of the formulas (R2Aa), (R2Ab), (R2Ac) or (R2Ad), with where each R 11 and each has the meanings given in claim 4, the cycle of Formula (R2Ac) optionally contains one or two double bonds and each cycle of formula (R2Ad) independently optionally contains one or two double bonds.

6. Process according to one of claims 1 to 5, characterized in that the diol in process step (ii) is aliphatic or cycloaliphatic.

7. Process according to claim 6, characterized in that the diol in process step (ii) is selected from the group consisting of 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2-bis(4- Hydroxycyclohexylpropane, tetrahydro-2,5-furandimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, cyclobutane-1,1-diyldimethanol, and 8-(hydroxymethyl)-3-tricyclo[5.2.1.02,6]decanyl]methanol, 2-butyl-2-ethyl-1,3-propanediol, 2-(2-Hydroxyethoxyjethanol, 2,2,4-trimethyl-1,3-pentanediol, 2,2-dimethylpropane-1,3-diol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,4:3,6-Dianhydrohexitol and a compound of formula (4), HO— (CH2) r — R 3 -(CH2)S -OH (4), where each r and each s independently represents a number between 0 and 4 and each R 3 independently represents a structure of the formulas (R3A), (R3B), (R3C) and (R3D) where the with , marked positions in formulas (R3A) to (R3D) are the positions where the (CH2) shown in formula (4) r -group or (CH2)s-group.

8. The process according to any one of claims 1 to 7, characterized in that the diaryl carbonate of process step (i) and / or the optional further diaryl carbonate of process step (ii) is selected from the group consisting of a compound of formula (5) wherein R, R and R" may each independently be the same or different and represent hydrogen, optionally branched C1-C34-alkyl, C1-C34-alkyl, C1-C34-aryl, a nitro group, a carbonyl-containing group, a carboxyl-containing group or a halogen group 9. Process according to one of claims 1 to 8, characterized in that in process step (i) 2.01 to 2.5, particularly preferably 2.05 to 2.2 moles of diaryl carbonate are used per 1 mole of the at least one dicarboxylic acid and in process step (iii) further diaryl carbonate is added.

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

11. The process according to claim 10, characterized in that the catalyst used in process step (i) is selected from the group consisting of alkylamines, imidazole (derivatives), guanidine-derived bases, l,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-l,4,5,6-tetrahydropyridine, 7-methyl-l,5,7-triazabicyclodec-5-ene, ethylimidazole, N,N-diisopropyl ethylamine (Hünig's base), pyridine, 1,1,3,3-tetramethylguanidine (TMG), 4-dimethylaminopyridine and derivatives, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), l,5-diazabicyclo[4.3.0]non-5-ene (DBN) and mixtures of these substances.

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

13. Process according to one of claims 1 to 12, characterized in that in process step (iii) at least one further diol is additionally reacted with the diol obtained directly from the mixture (I) obtained from process step (i) or, if a process step (ii) has been carried out, with the mixture (II) obtained directly from process step (ii).

14. Polyestercarbonate obtained by the process according to any one of claims 1 to 13, wherein the process necessarily comprises process step (ii).

15. Shaped body containing the polyester carbonate according to claim 14.

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