POLYESTERCARBONATES MADE FROM A DEFINED RATIO OF DIFFERENT DIOLS

Description

[0001] The present invention relates to copolyestercarbonates of the structural formula (1) with a defined ratio of different structural units resulting from diols, a molding composition, a molded part and a process for producing the corresponding polyestercarbonates.

[0002] 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.

[0003] While aromatic polycarbonates or polyesters often have a good property profile, they 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., transmission).

[0004] The disadvantage of aliphatic polycarbonates or polyester carbonates is often their low glass transition temperature. Therefore, it is advantageous to use cycloaliphatic alcohols as (co)monomers. Examples of such cycloaliphatic alcohols include TCD alcohol (tricyclodecanedimethanol; 8-(hydroxymethyl)-3-tricyclo[5.2.1.02,6]decanyl]methanol), cyclohexanediol, cyclohexanedimethanol, and bio-based diols based on 1,4:3,6-dianhydrohexitols such as isosorbide and the isomers isomannide and iosidid. To further increase the glass transition temperature, cycloaliphatic acids such as 1,2, 1,3, or 1,4-cyclohexanedicarboxylic acids or corresponding naphthalene derivatives can be used as (co)monomers. Depending on the choice of reactants, polyesters or polyester carbonates are then obtained. This application relates to copolyestercarbonates based on 1,4:3,6-dianhydrohexitols such as isosorbide orthe isomers, as well as cycloaliphatic diacids containing certain amounts of other diols to achieve improved properties. The invention further relates to a process for producing these copolyestercarbonates, which is characterized by the direct conversion of the raw materials and does not require raw materials that are difficult to handle, such as phosgene.

[0005] The polyesters of cyclohexanedicarboxylic acid and isosorbide are described by Oh et al. in Macromolecules 2013, 46, 2930-2940. US 2004 / 0092703 A1 also describes polyesters based on isosorbide. However, the present invention is preferably directed to polyester carbonates.

[0006] Polyesters are produced on an industrial scale, for example, by transesterification of corresponding ester-containing monomers with diols. Polyester is produced from 1,4-cyclohexane dimethanol and 1,4-cyclohexanedicarboxylic acid, starting with the dimethyl ester of the diacid (a blend of this polyester and polycarbonate: Xyrex® from DuPont).

[0007] 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 the preparation of polyester carbonates using phenyl ester as an intermediate step.

[0008] In EP 3026074 A1, Example 1 describes the direct reaction of diacid with phenol to form the corresponding ester. In Example 2 of EP 3026074 A1, a dimethyl ester is reacted with phenol. However, the yields for both variants of phenyl ester preparation can still be improved. Subsequently, the polyester carbonate is prepared. The polyester carbonate is produced from only one diol.

[0009] EP 3248999 A1 describes the production of a diphenyl ester in a solvent using phosgene. Since the subsequent reaction to form the aliphatic polyester carbonate requires no phosgene, combining a phosgene process with a transesterification process in one part of the plant is very disadvantageous. Therefore, the process described in EP 3248999 A1 is also not optimal, and here too, only one diol is used to produce the polymer. In WO2020 / 085686 A1, polyester carbonates are produced from isosorbide, cyclohexanedicarboxylic acid, and another diol, which can be cyclohexanedimethanol, for example. However, very high amounts of cyclohexanedimethanol are used here. Excessive amounts of cyclohexanedimethanol often have a negative impact on the thermal properties of the polymer. In particular, the glass transition temperature drops drastically.WO2019 / 093770 A1 also discloses polyester carbonates with structural units derived from isosorbide, cyclohexanedimethanol, diphenyl carbonate and cyclohexanedicarboxylic acid.

[0010] WO2019 / 147051 A1 discloses a two-step process employing an additional acid such as terephthalic acid. US 2009 / 105393 A1 discloses an isosorbide-based polycarbonate comprising: an isosorbide unit, an aliphatic unit derived from a C-14 to C-44 aliphatic diacid, a C-14 to C-44 aliphatic diol, or a combination thereof; and optionally, an additional unit different from the isosorbide and aliphatic units, wherein the isosorbide unit, the aliphatic unit, and the additional unit are each carbonates or a combination of carbonate and ester units. The common disadvantages of aliphatic polycarbonates or polyestercarbonates have already been discussed above. In the examples, no polymers derived from a combination of isosorbide, a cycloaliphatic diacid, and additionally an aliphatic diol are prepared.In addition, an activated carbonate is used for transesterification.

[0011] The simple preparation of aromatic polyester carbonates is described, for example, in WO 01 / 32742 A1. This document describes a direct synthesis or one-pot synthesis, i.e., a synthesis in which all structural elements constituting the subsequent polyester carbonate are already present as monomers at the beginning of the synthesis. The monomers used here are aromatic dihydroxy compounds such as bisphenol A, carboxylic acid diesters, and aromatic or linear aliphatic diacids. Because only aromatic polyester carbonates are prepared in this document, temperatures of 300 °C can be used in the condensation reaction to remove the resulting phenol. Such temperatures are not possible in the preparation of aliphatic polyester carbonates because aliphatic diols are eliminated at this temperature and / or tend to decompose thermally.At the same time, however, the high temperature is required to build up the desired high molecular weights. This particularly highlights the different reactivity of aliphatic and aromatic diols. It is known from the literature that, for example, isosorbide is rarely completely incorporated into a polymer, but that, depending on the chosen reaction conditions, up to 25% of the isosorbide is lost during the polymerization reaction. Therefore, a transfer of reaction conditions for aromatic diols to aliphatic diols is not easily possible. This is particularly evident from the fact that the reaction times for the polycondensation (corresponding to process step (ii)) in WO01 / 32742 A1 at higher temperatures are significantly longer than those observed according to the invention.

[0012] Likewise, JP1992-345616 A and DE2438053 A1 use aromatic building blocks and correspondingly high temperatures. For the reasons stated above, the teachings therein cannot be applied to aliphatic building blocks.

[0013] The not yet published application PCT / EP2019 / 084847 discloses a one-pot synthesis of a polyester carbonate comprising a cycloaliphatic dicarboxylic acid, a diaryl carbonate and an aliphatic dihydroxy compound.

[0014] The polyester carbonates described in EP 3026074 A1 and EP 3248999 A1 exhibit high glass transition temperatures. However, the structure of these polyester carbonates is very rigid. This is primarily a result of the isosorbide structure condensed into the polymer chain. The bicyclic substructure increases the glass transition temperature due to its rigid nature – however, it makes the polymer chain very inflexible; this can, in principle, lead to disadvantages. Park et al. describe that higher amounts of isosorbide in the polymer decrease the molecular weight (SA Park et al. Polymer 2017, 116, 153-159; pp. 155 / 156). The authors describe that the high melt viscosity prevents the molecular weight from increasing. Failure to reach a critical molecular weight can lead to insufficient mechanical properties. This is particularly important for inflexible polymer chains.The rigid chains require a relatively high molecular weight to entangle. If this is not the case, brittle behavior results (critical entanglement molecular weight).

[0015] Although cyclohexanedicarboxylic acid increases flexibility somewhat, the overall structure of the polymer chain remains quite rigid. This can lead to disadvantages during polymer production. Due to their inflexible nature, the reactants (chain ends) become heavier with increasing molecular weight. This limits the molecular weight, as described above. Furthermore, due to their rigid nature, viscosity increases significantly during polymer synthesis. To compensate for this, the temperature is often increased in the final phase of polycondensation during polymer production to achieve better flowability. However, this is only possible to a limited extent with aliphatic polymers, as their thermal stability is significantly lower than that of, for example, aromatic polyesters or polycarbonates.The increasing viscosity, which cannot be compensated by increasing the temperature, leads to insufficient mixing and reduced surface renewal. As a result, condensation products (such as phenol) can no longer be removed, and the polycondensation process ceases.

[0016] To achieve better surface renewal, WO2019147051 A1 describes the use of horizontal polymer reactors such as polymer kneaders. These exert high shear forces on the polymer; this increases surface renewal and allows polycondensation to continue. However, the high shear forces place enormous stress on the inflexible polymer.

[0017] The high shear stress can cause damage, which can be noticeable in a deterioration of the optical and mechanical properties.

[0018] Based on this prior art, the present invention was therefore based on the object of providing a polyestercarbonate comprising at least one 1,4:3,6-dianhydrohexitol and at least one specific cycloaliphatic dicarboxylic acid, which is characterized by sufficiently high molecular weights. "Sufficiently high molecular weights" is preferably understood to mean a polymer having a relative solution viscosity above 1.20, preferably 1.20 to 1.70, more preferably 1.22 to 1.65, and especially preferably 1.30 to 1.62, each measured in dichloromethane at a concentration of 5 g / l at 25°C using an Ubbelohde viscometer. Furthermore, the polyestercarbonates according to the invention should thus have improved processing properties and good mechanical properties. These should result in particular from the sufficiently high molecular weight.High molecular weights result, for example, from better surface renewal during the production process. A further objective was to provide the simplest possible process for producing polyester carbonates by melt transesterification. "Simple" is understood in particular as a process that requires minimal equipment, involves few steps, particularly purification steps, and / or is thus economically and ecologically advantageous. In particular, the process according to the invention should not require any feedstocks that are challenging to handle, especially phosgene.

[0019] At least one, preferably all, of the above-mentioned objects have been achieved by the present invention. Surprisingly, it has been found that the synthesis of a polyester carbonate from at least one cycloaliphatic diacid, at least one diaryl carbonate, at least one 1,4:3,6-dianhydrohexitol, and at least one further aliphatic dihydroxy compound by means of melt transesterification in a direct synthesis or one-pot synthesis, in which all structural elements constituting the later polyester carbonate are already present as monomers at the beginning of the synthesis, is possible. However, it has been found that a polymer with the appropriate molecular weight and thus also appropriate mechanical properties is obtained only if a certain amount of the at least one further diol HO-x-OH is used. In addition, this at least one further diol must preferably have at least one branching.Firstly, it was surprising that, despite the prejudices described in the prior art, a direct synthesis also works for the reaction of a cycloaliphatic dicarboxylic acid, a 1,4:3,6-dianhydrohexitol, and at least one further aliphatic dihydroxy compound HO-x-OH (or also referred to as "aliphatic diol" according to the invention), and a diaryl carbonate. Furthermore, it was completely surprising that the amount of the at least one further aliphatic dihydroxy compound HO-x-OH is important for achieving a good molecular weight increase. In this way, a process was discovered that makes a polyester carbonate accessible from cycloaliphatic diacids, a 1,4:3,6-dianhydrohexitol, and at least one further aliphatic dihydroxy compound HO-x-OH. This process is particularly simple, i.e., requires minimal equipment, requires few steps, especially purification steps, and is thus economically and ecologically advantageous.

[0020] Furthermore, it was found that the incorporation of small amounts of additional aliphatic dihydroxy compounds HO-x-OH, especially the incorporation of branched aliphatic dihydroxy compounds, increases surface renewal during synthesis. It was particularly surprising that only certain small amounts of certain diols lead to favorable properties, whereas higher amounts are surprisingly detrimental. It was surprising that even the incorporation of small amounts of additional diols significantly increases surface renewal and thus the molecular weight. It was particularly surprising that branched diols condense well into the polymer chain despite the steric hindrance. One skilled in the art would have expected that steric hindrance would impede the molecular weight buildup.Overall, polyester carbonates were thus provided whose structural elements are responsible for a good balance between rigidity and flexibility of the polymer chains, but which also have a sufficiently large molecular weight overall, which leads to correspondingly good mechanical properties.

[0021] Equally surprising, it was found that the incorporation of additional aliphatic dihydroxy compounds HO-X-OH, which exhibit branching, leads to polymers with lower shear viscosity. This is particularly true even when a higher solution viscosity is present, and equally true when a comparable Tg is present.

[0022] The process for producing a polyester carbonate according to the invention can be schematically described, for example, by the reaction of cyclohexanedicarboxylic acid, isosorbide, an additional diol HO-R-OH and diphenyl carbonate, as follows: (The mention of these three specific starting substances serves only to explain the invention and is not to be understood as limiting)

[0023] In the direct synthesis according to the invention, gas evolution was initially observed (carbon dioxide escaped). If a sample is taken from the mixture after the gas evolution has essentially subsided, it can be analytically demonstrated that oligomers have already formed. These oligomers condense in a further step to form the polyester carbonate according to the invention. Therefore, according to the invention, a polyester carbonate is provided comprising the structural formula (1) in the A per repeating unit independently represents at least either structural unit (A) or structural unit (B), where (A) represents the chemical formula (2) and (B) represents the chemical formula (3) *-x-* (3), where x represents a branched alkylene group having 4 to 20, preferably 5 to 15 carbon atoms, which may optionally be interrupted by at least one heteroatom, or a cycloalkylene group having at least one branch, where the cycloalkylene group has 4 to 20, preferably 5 to 15 carbon atoms, may optionally be interrupted by at least one heteroatom, and where the cycloalkylene group may optionally contain several rings, y each independently represents the chemical formula (IIIa) or (IIIb) in which B each independently represents a CH 2 group or a heteroatom selected from the group consisting of O and S, preferably a CH 2 group or an oxygen atom, R 1 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, n is a number between 0 and 3, preferably 0 or 1 and 0 < x < 1 , where the * each indicate the position at which the chemical formulas are incorporated into the polyester carbonate, characterized in that the polyester carbonate comprises 98 mol% to 75 mol%, preferably 97 mol% to 80 mol%, particularly preferably 96 mol% to 82 mol% of the structural unit (A) and 2 mol% to 25 mol%, preferably 3 mol% to 20 mol%, particularly preferably 4 mol% to 18 mol% of the structural unit (B), in each case based on the sum of the structural units (A) and (B), and in that the polyester carbonate has a relative solution viscosity, measured in dichloromethane at a concentration of 5 g / l at 25 °C using an Ubbelohde viscometer, of 1.20 to 1.70, preferably 1.23 to 1.67, particularly preferably 1.25 to 1.65.

[0024] In structural formula (1), component "A" is defined in more detail. A can represent either at least (A) or (B). This can be freely selected independently for each repeating unit. According to the invention, the term "repeating unit" preferably refers to the structure framed either by "[...] 1-x" or by "[...] x." Thus, structural formula (1) already comprises two different repeating units, which have either a carbonate structure or an ester structure in addition to A. For each repeating unit of structural formula (1), A independently represents at least either structural unit (A) or structural unit (B). The use of the term "at least" means that A can also stand for another structural unit (C). However, the polyestercarbonate according to the invention always necessarily comprises structural units (A) and (B) in the defined quantitative ratios to one another.

[0025] Preferably, A consists only of the structural units (A) and (B) and does not comprise any further structural unit (C). In this case, A represents either structural unit (A) or structural unit (B) independently of one another for each repeating unit of structural formula (1). Furthermore, it is apparent to the person skilled in the art that (A) can have a plurality of different structures of formula (2). Likewise, (B) can have a plurality of different structures of formula (3). Preferably, however, (A) has only one structure of formula (2). Equally preferably, however, (B) has only one structure of formula (3). Particularly preferably, (A) and (B) have only one structure of formula (2) or (3).

[0026] It has surprisingly been found that when the amount of component (B) is within the range defined in the claims, the molecular weight buildup works particularly well, so that a polyestercarbonate can be obtained which has a relative solution viscosity of 1.20 to 1.70. If the amount of (B) is higher, surprisingly only a slight molecular weight buildup occurs. It was further advantageous if (B) had 2 to 11, preferably 3 to 10, carbon atoms. This resulted in polyestercarbonates which had good mechanical properties, in particular good elongation at break and good elastic moduli. Furthermore, the polyestercarbonates according to the invention exhibit good impact strength.

[0027] According to the invention, a distinction is made between a repeating unit, a structural unit, and a structural motif. As already described above, a repeating unit is preferably understood to be the structure enclosed in formula (1) by the brackets [...] 1-x or the bracket [...] x. Structural formula (1) thus already comprises two repeating units. Furthermore, it has at least the structural units (A) and (B) through A. The structural units (A) and (B) (or possibly also (C)) are each present once in a repeating unit. They can be different per repeating unit. According to the invention, the term structural unit is preferably used for a structure that is not a repeating unit per se, since it has neither a carbonate structure nor an ester structure. Furthermore, it does not represent a structural motif.The term is therefore used for a structure that is smaller than a repeating unit and a structural motif. According to the invention, a structural motif is preferably understood to mean a structure that can be derived from a monomer used by reaction to form a polymer. Thus, according to the invention, a structural motif is understood to mean at least the following structures: . The first structural motif is derived from a diol, which is incorporated into the polymer of structural formula (1) by reaction. The oxygen is thus either part of the carbonate or ester unit in structural formula (1). The second structural motif is derived in a similar manner from a dicarboxylic acid. The third structural motif is also derived in a similar manner from a 1,4:3,6-dianhydrohexitol.

[0028] In contrast, a structural unit according to the invention therefore does not contain oxygen and is therefore not directly assignable to a monomer. Structural unit (A) thus corresponds to the structural motif except for the oxygen atom. Structural unit (B) corresponds to the structural motif *-xO-* except for the oxygen atom.

[0029] In particular, it is preferred that the polyester carbonate according to the invention is characterized in that the polyester carbonate comprises the following repeating units (i) to (iv) in any order where a, b, c, and d each independently represent a natural number indicating the average number of repeating units. Here, too, the repeating units are enclosed in parentheses. The indices a, b, c, and d are preferably adjusted to yield the solution viscosity according to the invention. It was surprising according to the invention that the numbers a, b, c, and d are so high that sufficiently high molecular weights were obtained.

[0030] According to the invention, it is preferred that the polyester carbonate consists of at least 80 wt. %, preferably 85 wt. %, particularly preferably 90 wt. %, based on the total weight of the polyester carbonate. The polyester carbonate according to the invention therefore preferably has only small amounts of structures other than those defined in the structural formula (1). It is further preferred that the polyester carbonate according to the invention has no functional structures other than carbonate and / or ester structures. This means that the maximum 20 wt. %, preferably maximum 15 wt. %, particularly preferably maximum 10 wt. % which do not consist of the structural formula (1) can preferably be derived from other diols or dicarboxylic acids, which in turn lead to carbonate or ester structures upon incorporation into the polyester carbonate.

[0031] It is preferred that the polyester carbonate according to the invention is characterized in that 1 mol% to 20 mol%, preferably 2 mol% to 18 mol%, particularly preferably 3 mol% to 15 mol% of the polyester carbonate consists of the structural motif *-xO-*, based on the total sum of the following structural motifs *-xO-*,

[0032] According to the invention, the ratio of monomers with hydroxy functionalities to dicarboxylic acids used in the polyester carbonate can be freely adjusted. The more dihydroxy compounds used, the more carbonate structures result. The more dicarboxylic acid, the more ester structures. As a result, the ratio of carbonate structures to ester structures can also be freely selected. It has been shown that this is particularly due to the process according to the invention, in which all monomers constituting the polyester carbonate are already present at the beginning of the synthesis. This thus leads to polyester carbonates with specifically adjustable properties. However, the ratio of the two dihydroxy compounds that lead to structural units (A) and (B) must be kept within the inventive range.It has proven advantageous if the amount of the structural motif *-xO-*, which without the oxygen atom constitutes the structural unit (B), is not too high. If it is too low, the overall molecular weight structure is poorer. If it is too high, the glass transition temperature of the polyester carbonate is not optimal. The sum of the carbonate structures always results from the sum of the dihydroxy compounds and dicarboxylic acids used.

[0033] Preferably, (A) is selected from at least one of the structures Most preferred is (A)

[0034] Preferably, x represents a branched alkylene group having 4 to 20, preferably 5 to 15 carbon atoms, more preferably 5 to 11 carbon atoms, most preferably 5 to 10 carbon atoms, which may optionally be interrupted by at least one heteroatom. The heteroatom which may optionally interrupt the branched alkylene group is preferably oxygen or sulfur, more preferably oxygen. More preferably, the branched alkylene group contains only one heteroatom or no heteroatom. More preferably, the branched alkylene group does not have a heteroatom. If at least one heteroatom is present in the alkylene group, the stated number of carbon atoms refers to the total number of carbon atoms in the alkylene group. For example, the group -CH 2 -CH 2 -O-CH 2 -CH 2 - contains 4 carbon atoms.The term "branched" refers to the branches on aliphatic carbon chains known to those skilled in the art. This means that the branched alkylene group preferably comprises at least one tertiary and / or at least one quaternary carbon atom. More than one branch may be present in the branched alkylene group. The branches preferably have chain lengths of 1 to 5 carbon atoms, more preferably 1 to 4, and most preferably 1 to 3 carbon atoms. These carbon atoms of the branches count towards the total carbon number of the branched alkylene group. This means that, for example, a branched alkylene group of -CH 2 -C(CH 3 ) 2 -CH 2 - has 5 carbon atoms.

[0035] If, according to the invention, x is a cycloalkylene group with at least one branch and where the cycloalkylene group has 4 to 20, preferably 5 to 15 carbon atoms, can optionally be interrupted by at least one heteroatom and where the cycloalkylene group can optionally contain several cycles, the above-mentioned statements apply to the heteroatom. The heteroatom, which can optionally interrupt the cycloalkylene group, is preferably oxygen or sulfur, particularly preferably oxygen. Particularly preferably, the cycloalkylene group contains only one heteroatom or no heteroatom. Particularly preferably, the cycloalkylene group does not have a heteroatom. The cycloalkylene group preferably has at least one, preferably one, cycle with 4 to 6 carbon atoms.In particular, it is preferred that the cycloalkylene group has a total of 4 to 20, preferably 5 to 15, carbon atoms and a cycle with 4 to 5 carbon atoms. The carbon atoms of the cycle count towards the total number of carbon atoms in the cycloalkylene group. This means that a tetramethylcyclobutenyl group has a total of 8 carbon atoms and a cycle with 4 carbon atoms. Furthermore, the cycloalkylene group has at least one branch. These branches can be present in the optionally present cycloaliphatic chain and / or the cycle. The branches are preferably present in the cycle. The term "branching" in relation to the cycloalkylene group refers to the branches known to the person skilled in the art. This means that the branched cycloalkylene group preferably comprises at least one tertiary and / or at least one quaternary carbon atom.It is clear that the two tertiary carbon atoms connecting the cycle to the polymer chain are not understood as branches according to the invention. This preferably means that if the cycloalkylene group has at least one branch at least on the cycle, this cycle then has at least one tertiary and / or quaternary carbon atom in addition to the two tertiary carbon atoms connecting the cycle to the polymer chain (see also the "*" in formula (3)). It is also possible for the branch to be present in an alkyl group present on the cycle (for example, if x is 2,2-bis(4-cyclohexylene)propane). Particularly preferably, "branched" with reference to the cycloalkylene group means that the group has at least one quaternary carbon atom.Preferably, x is a cycloalkylene group having 5 to 15 carbon atoms with a cycle which optionally has at least one branch, preferably has at least one branch and has at least one cycle, preferably a cycle with 4 to 6 carbon atoms, particularly preferably 4 to 5 carbon atoms.

[0036] Overall, it is preferred according to the invention that x has 2 to 10 carbon atoms.

[0037] Particularly preferably, *-x-* is selected from the group consisting of 2,2-bis(4-cyclohexylene)propane, 2-butyl-2-ethyl-1,3-propylene, 2,2,4,4-tetramethyl-1,3-cyclobutylene, 2,2,4-trimethyl-1,3-pentylene, 2,2-dimethylpropan-1,3-ylene, 8-(methylene)-3-tricyclo[5.2.1.02,6]decanyl]methylene, and any mixtures thereof. In particular, it is preferred that x in *-x-* is selected from the group consisting of 2-butyl-2-ethyl-1,3-propylene, 2,2,4,4-tetramethyl-1,3-cyclobutylene, 2,2,4-trimethyl-1,3-pentylene, 2,2-dimethylpropan-1,3-ylene, and any mixtures thereof. Likewise, it is preferred that x in *-x-* is selected from the group consisting of 2-butyl-2-ethyl-1,3-propylene, 2,2,4,4-tetramethyl-1,3-cyclobutylene, 2,2,4-trimethyl-1,3-pentylene, 2,2-dimethylpropan-1,3-ylene, and any mixtures thereof.It is most preferably preferred that x in *-x-* is selected from the group consisting of 2-butyl-2-ethyl-1,3-propylene, 2,2,4,4-tetramethyl-1,3-cyclobutylene, 2,2,4-trimethyl-1,3-pentylene, 2,2-dimethylpropan-1,3-ylene, and any mixtures thereof. As already explained above, x can be a mixture of the above-mentioned structures. However, x preferably represents only one of the structures.

[0038] According to the invention, y each independently represents the chemical formula (IIIa) or (IIIb) in which B each independently represents a carbon atom or a heteroatom selected from the group consisting of O and S, preferably a carbon atom or an oxygen atom, R 1 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, n is a number between 0 and 3, preferably 0 or 1.

[0039] It is understood that if R 1 represents a single bond, R 1 therefore contains zero carbon atoms.

[0040] In particular, it is preferred that y is selected from the group consisting of 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, 1,2-cyclohexanedimethylene, 1,3-cyclohexanedimethylene, 1,4-cyclohexanedimethylene, 2,2-bis(4-cyclohexylene)propane, tetrahydro-2,5-furandimethylene, 2-butyl-2-ethyl-1,3-propylene, 2-(2-ethyloxy)ethylene, 2,2,4,4-tetramethyl-1,3-cyclobutylene, 2,2,4-trimethyl-1,3-pentylene, 2,2-dimethylpropan-1,3-ylene, cyclobutane-1,1-diyldimethylene, 8-(methylene)-3-tricyclo[5.2.1.0 2,6 ]decanyl]methylene, 1,2-propylene, 1,3-propanylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,8-octylene, and any mixtures thereof. Particularly preferably, y is selected from the group consisting of 1,2-cyclohexylene, 1,3-cyclohexylene, and 1,4-cyclohexylene.

[0041] In addition to the structures mentioned, small amounts of other acids can also be used for y. Particularly preferably, y thus additionally has up to 20 mol%, further preferably up to 10 mol% and very particularly preferably up to 5 mol% of a structural formula y1 and / or y2. Preferably, y1 does not have a cycle. Particularly preferably, y1 is selected from the group consisting of 2,2,4-trimethylbutylene, 2,4,4-trimethylbutylene, 2,2,5-trimethylbutylene and 3,3-dimethylpropylene. It is also preferred that y2 is selected from the group consisting of structures derived from the following dicarboxylic acids: isophthalic acid, terephthalic acid, 2,5-furandicarboxylic acid and 2,6-naphthalenedicarboxylic acid. It is clear here that the resulting ester group does not belong to the structural unit y2. In these cases, the term aliphatic polyester carbonate is still preferably used according to the invention.However, the polyester carbonate according to the invention particularly preferably does not contain any aromatic structures derived from aromatic dicarboxylic acids.

[0042] It is preferred if the polyester carbonate according to the invention is characterized in that the molar ratio of the sum of the structural motifs *-xO-* and to the structural motif 6:4 to 9:1, preferably 7:3 to 8:2. As already explained above, this ratio can be freely selected in the inventive polyestercarbonate. This achieves a good balance between the rigidity and flexibility of the polymer chains, resulting in correspondingly good mechanical properties.

[0043] It is also preferred if the polyester carbonate according to the invention is characterized in that at least 45 mol%, preferably at least 50 mol% of the polyester carbonate consists of the structural motif consists of the total sum of the following structural motifs *-xO-* This amount is particularly advantageous for achieving a high glass transition temperature.

[0044] Furthermore, the invention does not rule out the possibility that A additionally represents the structural unit (C). (C) here comprises aromatic structures. However, these are preferably present only in small proportions. Preferably, (C) is additionally present in an amount of up to 20 mol%, further preferably up to 10 mol%, and very particularly preferably up to 5 mol%, based on the total sum of the structural units (A), (B), and (C). The ratio of (A) and (B) defined in the claim remains the same. In these cases, the invention still preferably refers to an aliphatic polyester carbonate. However, the polyester carbonate according to the invention particularly preferably does not have a structural unit (C). Likewise, it is preferred that the polyester carbonate according to the invention has neither a structural unit (C) nor an aromatic structural unit y2. As a rule, aromatic compounds in polyester carbonates reduce their UV stability and weather resistance.This is particularly disadvantageous for outdoor applications. Furthermore, aromatic components in a polyester carbonate reduce the surface hardness of molded articles produced from it, which may require coating. Furthermore, diphenyl esters of aromatic acids, for example, which may form intermediately, represent stable intermediates that can slow down the polycondensation. This may require the use of additional specific catalysts. Accordingly, it is preferred that A consists of (A) and (B).

[0045] These additional structural units (C) are preferably selected from the group of structural units derived from the following diols: bisphenol A, 1,1-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' is each C1-C4 alkyl, aralkyl, or aryl, preferably methyl or phenyl, most preferably methyl. According to the invention, the term "derived from" preferably means that the corresponding monomer is introduced into the resulting polyester carbonate via the hydroxyl group or acid group, either by forming an ester group or by forming a carbonate group.

[0046] According to the invention, it is preferred that, if additional building blocks are present in structural formula (1) or in structural formula (1), the previously defined mol% and ratios are maintained. The amount of the newly defined building block is then added.

[0047] It is also preferred that the defined mol % in the polyester carbonate according to the invention be determined via 1< H NMR. This method is familiar to those skilled in the art. The polyester carbonate can, for example, be dissolved in CDCl 3 and the corresponding peaks of the structural units identified. The ratios and proportions can be determined via the integrals. On the other hand, the mol % according to the invention can also be determined via the amounts and ratios of the monomers used. It must be assumed that all monomers are fully incorporated into the polyester carbonate in the same ratio. This allows the skilled person to adjust the ratio in advance.

[0048] The polyestercarbonate according to the invention has a relative solution viscosity of 1.20 to 1.70, preferably 1.23 to 1.67, particularly preferably 1.25 to 1.65. The relative solution viscosity (ηrel; 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 of 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 polyestercarbonate 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, a calibration of the Ubbelohde viscometer is first carried out by measuring the pure solvents dichloromethane, trichloroethylene and tetrachloroethylene (at least 3 measurements are always carried out, at most 9 measurements).The actual calibration then takes place using 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.

[0049] Here is the method for determining eta rel.

[0050] In a further aspect of the present invention, a process for producing the polyester carbonate according to the invention by melt transesterification is provided, comprising the steps (i) Reaction of at least one dicarboxylic acid of chemical formula (IIa) or (IIb) wherein B each independently represents a CH 2 group or a heteroatom selected from the group consisting of O and S, preferably a CH 2 group or an oxygen atom, R 1 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, with at least one diaryl carbonate using at least one catalyst and in the presence of a mixture of dihydroxy compounds, comprising component (A) at least one 1,4:3,6-dianhydrohexitol and component (B) at least one further aliphatic dihydroxy compound of the chemical formula (I) HO-X-OH (I), in which X represents a branched alkylene group having 4 to 20, preferably 5 to 15 carbon atoms,which may optionally be interrupted by at least one heteroatom or a cycloalkylene group with at least one branch, wherein the cycloalkylene group has 4 to 20, preferably 5 to 15 carbon atoms, may optionally be interrupted by at least one heteroatom and wherein the cycloalkylene group may optionally contain several cycles, and (ii) further condensation of the mixture obtained from process step (i) at least with removal of the chemical compound split off during the condensation, characterized in that the mixture of dihydroxy compounds 98 mol% to 75 mol%, preferably 97 mol% to 80 mol%, particularly preferably 96 mol% to 82 mol% of component (A) and 2 mol% to 25 mol%, preferably 3 mol% to 20 mol%, particularly preferably 4 mol% to 18 mol% of component (B), each based on the sum of components (A) and (B). According to the invention, in process step (i) at least the reaction of at least one cycloaliphatic dicarboxylic acid with at least one diaryl carbonate takes place. However, according to the invention, it cannot be ruled out that further reactions may occur due to the presence of the at least one 1,4:3,6-dianhydrohexitol (hereinafter also component (A)) and the at least one further aliphatic dihydroxy compound (hereinafter also component (B)) (it should be noted here that component (A) and component (B) subsequently lead to the structural units (A) and (B) in the polyester carbonate according to the invention).In fact, examples have demonstrated that oligomers are formed as early as process step (i), which exhibit a mass difference in the MALDI-ToF mass spectrometer corresponding to a unit of component (A) and / or component (B) with carbonate (with loss of the two hydroxyl groups). This means that further reactions can occur in process step (i) in addition to the formation of the diester. However, according to the invention, this also means that the reaction of all cycloaliphatic dicarboxylic acids present with the stoichimetrically corresponding diaryl carbonates is not possible. must have taken place completely before process step (ii) 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) initiated, for example by applying a vacuum to remove the chemical compound split off during the condensation. As already explained above, process steps (i) and (ii) may not be clearly separated from one another according to the invention. Process step (i)

[0051] The process according to the invention is referred to as direct synthesis or one-pot synthesis, since in process step (i) all structural elements constituting the later polyester carbonate are already present as monomers. This preferably means that, according to the invention, all aliphatic dihydroxy compounds (in any case components (A) and (B)), all cycloaliphatic dicarboxylic acids, and also all diaryl carbonates are present in this step, even if more than just the dihydroxy compounds of components (A) and (B), a cycloaliphatic dicarboxylic acid, and / or a diaryl carbonate are present. Thus, it is preferred according to the invention that all monomers that are condensed to form the polyester carbonate in process step (ii) are already present during process step (i). The invention can also encompass the embodiment in which a small proportion of the at least one diaryl carbonate is additionally added in process step (ii).This can 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. However, it is necessary that the at least one diaryl carbonate added in small amounts in process step (ii) corresponds to the at least one diaryl carbonate present in process step (i), so that all structural elements constituting the subsequent polyester carbonate are still present as monomers in process step (i) and no further structural elements are added. In this sense, it can still be referred to as a direct synthesis or one-pot synthesis.

[0052] Furthermore, the invention does not rule out the presence of aromatic dihydroxy compounds and / or aromatic dicarboxylic acids in process step (i). 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 dihydroxy compound (component (C)) in process step (i), based on the total amount of dihydroxy compound used. The ratio of components (A) and (B) defined in the claim remains the same. Likewise, it is particularly preferred that, in process step (i), additionally containing up to 20 mol%, further preferably up to 10 mol%, and very particularly preferably up to 5 mol% of an aromatic dicarboxylic acid in process step (i), based on the total amount of dicarboxylic acid used, optionally also in addition to the aromatic dihydroxy compound.In these cases, the invention still preferably refers to an aliphatic polyester carbonate. However, it is particularly preferred that no aromatic dihydroxy compound is used in process step (i). Likewise, it is preferred that no aromatic dicarboxylic acid is used in process step (i). Likewise, it is preferred that neither an aromatic dihydroxy compound nor an aromatic dicarboxylic acid is used in process step (i). 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 may lead to the need for painting. In addition, diphenyl esters of aromatic acids, for example, which can form intermediately, represent stable intermediates that can slow down the polycondensation.This may require the use of additional specific catalysts.

[0053] These additional aromatic dihydroxy compounds (component (C)) are preferably selected from the group consisting of bisphenol A, 1,1-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) wherein in these formulas (I) to (III) R' each represents C1-C4 alkyl, aralkyl or aryl, preferably methyl or phenyl, most preferably methyl.

[0054] These additional aromatic dicarboxylic acids are preferably selected from the group consisting of isophthalic acid, terephthalic acid, 2,5-furandicarboxylic acid, and 2,6-naphthalenedicarboxylic acid. It is known that small amounts of these aromatic diacids can reduce the water absorption of an aliphatic polyester carbonate.

[0055] According to the invention, at least one 1,4:3,6-dianhydrohexitol is used as component (A) in process step (i). 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 preferred that component (A) consists of isosorbide.

[0056] According to the invention, at least one further aliphatic dihydroxy compound (component (B)) is used in process step (i). It is preferred that component (B) consists of two further aliphatic dihydroxy compounds. It is also preferred that component (B) consists of one further aliphatic dihydroxy compound. Thus, it is particularly preferred that component (A) consists of isosorbide and component (B) consists of one further aliphatic dihydroxy compound. Optionally, a component (C) comprising an aromatic dihydroxy compound (see above) may also be present in the mixture of dihydroxy compounds.

[0057] It is preferred that the at least one further aliphatic dihydroxy compound has the chemical formula (I): HO-X-OH (I), in which X represents a linear alkylene group having 2 to 22, preferably 2 to 15 carbon atoms, particularly preferably 2 to 10 carbon atoms, which may optionally be interrupted by at least one heteroatom, a branched alkylene group having 4 to 20, preferably 5 to 15 carbon atoms, which may optionally be interrupted by at least one heteroatom or a cycloalkylene group having 4 to 20, preferably 5 to 15 carbon atoms, which may optionally be interrupted by at least one heteroatom and wherein the cycloalkylene group may optionally contain a plurality of rings and may each optionally be branched.

[0058] In particular, it is preferred that in formula (I) X represents a branched alkylene group having 4 to 20, preferably 5 to 15 carbon atoms, which may optionally be interrupted by at least one heteroatom, or a cycloalkylene group having at least one branch, wherein the cycloalkylene group has 4 to 20, preferably 5 to 15 carbon atoms, may optionally be interrupted by at least one heteroatom, and wherein the cycloalkylene group may optionally contain several cycles.

[0059] If, according to the invention, X is a linear alkylene group which may optionally be interrupted by at least one heteroatom, it preferably has 2 to 15, particularly preferably 2 to 12, very particularly preferably 2 to 11, especially preferably 2 to 10, further preferably 2 to 6 and further preferably 3 to 4 carbon atoms. The heteroatom which may optionally interrupt the alkylene group is preferably oxygen or sulfur, particularly preferably oxygen. The alkylene group particularly preferably contains only one heteroatom or no heteroatom. If at least one heteroatom is present in the alkylene group, the stated number of carbon atoms refers to the total number of carbon atoms in the alkylene group. For example, the group -CH 2 -CH 2 -O-CH 2 -CH 2 - contains 4 carbon atoms.According to the invention, it is preferred that the linear alkylene group, which is optionally interrupted by at least one heteroatom, has fewer than 12, particularly preferably fewer than 10, carbon atoms. The alkylene group particularly preferably does not have any heteroatoms.

[0060] X preferably represents a branched alkylene group having 4 to 20, preferably 5 to 15 carbon atoms, more preferably 5 to 11 carbon atoms, most preferably 5 to 10 carbon atoms, which may optionally be interrupted by at least one heteroatom. The heteroatom which may optionally interrupt the branched alkylene group is preferably oxygen or sulfur, more preferably oxygen. More preferably, the branched alkylene group contains only one heteroatom or no heteroatom. More preferably, the branched alkylene group does not have a heteroatom. If at least one heteroatom is present in the alkylene group, the stated number of carbon atoms refers to the total number of carbon atoms in the alkylene group. For example, the group -CH 2 -CH 2 -O-CH 2 -CH 2 - contains 4 carbon atoms.The term "branched" refers to the branches on aliphatic carbon chains known to those skilled in the art. This means that the branched alkylene group preferably comprises at least one tertiary and / or at least one quaternary carbon atom. More than one branch may be present in the branched alkylene group. The branches preferably have chain lengths of 1 to 5 carbon atoms, more preferably 1 to 4, and most preferably 1 to 3 carbon atoms. These carbon atoms of the branches count towards the total carbon number of the branched alkylene group. This means that, for example, a branched alkylene group of -CH 2 -C(CH 3 ) 2 -CH 2 - has 5 carbon atoms.

[0061] If, according to the invention, X is a cycloalkylene group having 4 to 20, preferably 5 to 15 carbon atoms, which may optionally be interrupted by at least one heteroatom, and where the cycloalkylene group may optionally contain several cycles and each may optionally be branched, the above-mentioned statements apply to the heteroatom. The heteroatom, which may optionally interrupt the cycloalkylene group, is preferably oxygen or sulfur, particularly preferably oxygen. Particularly preferably, the cycloalkylene group contains only one heteroatom or no heteroatom. Particularly preferably, the cycloalkylene group does not have a heteroatom. The cycloalkylene group preferably has at least one, preferably one, cycle with 4 to 6 carbon atoms.In particular, it is preferred that the cycloalkylene group has a total of 4 to 20, preferably 5 to 15, carbon atoms and a cycle with 4 to 5 carbon atoms. The carbon atoms of the cycle count towards the total number of carbon atoms in the cycloalkylene group. This means that a tetramethylcyclobutenyl group has a total of 8 carbon atoms and a cycle with 4 carbon atoms. Furthermore, the cycloalkylene group can have at least one branch. This is particularly preferred. If branches are present, they can be present in the optionally present cycloaliphatic chain and / or the cycle. The branches are preferably present in the cycle.X is preferably a cycloalkylene group having 5 to 15 carbon atoms with a cycle which optionally has at least one branch, preferably has at least one branch and has at least one cycle, preferably a cycle with 4 to 6 carbon atoms, particularly preferably 4 to 5 carbon atoms.

[0062] If, according to the invention, X is a branched cycloalkylene group having 4 to 20, preferably 5 to 15 carbon atoms, which may optionally be interrupted by at least one heteroatom and where the cycloalkylene group may optionally contain multiple rings, the above-mentioned statements apply to the heteroatom. The heteroatom which may optionally interrupt the cycloalkylene group is preferably oxygen or sulfur, particularly preferably oxygen. The cycloalkylene group particularly preferably contains only one heteroatom or no heteroatom. The cycloalkylene group particularly preferably has no heteroatom. The cycloalkylene group preferably has at least one, preferably one, ring with 4 to 6 carbon atoms. In particular, it is preferred that the cycloalkylene group has a total of 4 to 20, preferably 5 to 15 carbon atoms and one ring with 4 to 5 carbon atoms.The carbon atoms of the cycle are added to the total number of carbon atoms in the cycloalkylene group. This means that a tetramethylcyclobutenyl group has a total of 8 carbon atoms, with a cycle of 4 carbon atoms. Furthermore, the cycloalkylene group has at least one branch. The branches can be present in the optionally present cycloaliphatic chain and / or the cycle. Preferably, the branches are present in the cycle.

[0063] The term "branching" in relation to the cycloalkylene group refers to the branches known to those skilled in the art. This means that the branched cycloalkylene group preferably comprises at least one tertiary and / or at least one quaternary carbon atom. It is clear that the two tertiary carbon atoms connecting the cycle to the polymer chain are not considered branches according to the invention. This preferably means that if the cycloalkylene group has at least one branch at least on the cycle, this cycle then has at least one tertiary and / or quaternary carbon atom in addition to the two tertiary carbon atoms connecting the cycle to the polymer chain (see also the "*" in formula (3)). It is also possible for the branching to be present in an alkyl group present on the cycle (for example, if x is 2,2-bis(4-cyclohexylene)propane).Particularly preferably, "branched" with respect to the cycloalkylene group means that the group has at least one quaternary carbon atom. X is preferably a cycloalkylene group having 5 to 15 carbon atoms with a cycle, which optionally has at least one branch, preferably has at least one branch and at least one cycle, preferably a cycle with 4 to 6 carbon atoms, particularly preferably 4 to 5 carbon atoms.

[0064] Overall, it is preferred according to the invention that the at least one further aliphatic dihydroxy compound has 2 to 10 carbon atoms.

[0065] The process according to the invention is particularly preferably characterized in that the at least one further aliphatic dihydroxy compound 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-butyl-2-ethyl-1,3-propanediol, 2-(2-hydroxyethoxy)ethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2-dimethylpropane-1,3-diol, cyclobutane-1,1-diyldimethanol, 8-(Hydroxymethyl)-3-tricyclo[5.2.1.02,6]decanyl]methanol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol and any mixtures thereof.In particular, it is preferred that the at least one further aliphatic dihydroxy compound is selected from the group consisting of 2-butyl-2-ethyl-1,3-propanediol, 2-(2-hydroxyethoxy)ethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2-dimethylpropane-1,3-diol, cyclobutane-1,1-diyldimethanol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol and any mixtures thereof. It is also preferred that the at least one further aliphatic dihydroxy compound is selected from the group consisting of 2-butyl-2-ethyl-1,3-propanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2-dimethylpropane-1,3-diol, cyclobutane-1,1-diyldimethanol, 1,4-butanediol and any mixtures thereof.It is very particularly preferred that the at least one further aliphatic dihydroxy compound is selected from the group consisting of 2-butyl-2-ethyl-1,3-propanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2-dimethylpropane-1,3-diol, cyclobutane-1,1-diyldimethanol and any mixtures thereof.

[0066] It is also preferred that the process according to the invention is characterized in that the at least one further aliphatic dihydroxy compound is selected from the group consisting of 2,2-bis(4-hydroxycyclohexyl)propane, 2-butyl-2-ethyl-1,3-propanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2-dimethylpropane-1,3-diol, 8-(hydroxymethyl)-3-tricyclo[5.2.1.02,6]decanyl]methanol and any mixtures thereof. In particular, it is preferred that the at least one further aliphatic dihydroxy compound is selected from the group consisting of 2-butyl-2-ethyl-1,3-propanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2-dimethylpropane-1,3-diol and any mixtures thereof.It is also preferred that the at least one further aliphatic dihydroxy compound is selected from the group consisting of 2-butyl-2-ethyl-1,3-propanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2-dimethylpropane-1,3-diol, and any mixtures thereof. It is most preferably preferred that the at least one further aliphatic dihydroxy compound is selected from the group consisting of 2-butyl-2-ethyl-1,3-propanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2-dimethylpropane-1,3-diol, and any mixtures thereof.

[0067] Likewise, in process step (i) according to the invention, at least one cycloaliphatic dicarboxylic acid is used. It is preferred that the at least one cycloaliphatic dicarboxylic acid is selected from a compound of the chemical formula (IIa), (IIb) or mixtures thereof. wherein B each independently represents a CH 2 group or a heteroatom selected from the group consisting of O and S, preferably a CH 2 group or an oxygen atom, R 1 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.

[0068] It is understood that if R 1 represents a single bond, R 1 therefore contains zero carbon atoms.

[0069] In particular, it is preferred that the at least one cycloaliphatic dicarboxylic acid 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. Very particular preference is given to 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, or 1,2-cyclohexanedicarboxylic acid.

[0070] In addition to the cycloaliphatic acid, small amounts of other aliphatic acids can also be used. Particularly preferably, up to 20 mol%, further preferably up to 10 mol%, and most preferably up to 5 mol% of a further aliphatic acid that is not a cycloaliphatic acid is additionally present in process step (i). The further aliphatic acid is preferably 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.

[0071] Likewise, in process step (i) according to the invention, at least one diaryl carbonate is used. It is preferred that the at least one diaryl carbonate is selected from the group consisting of a compound of formula (2) wherein R, R' and R" are each independently the same or different and represent hydrogen, optionally branched C1-C34alkyl, C7-C34alkylaryl, C6-C34aryl, a nitro group, a carbonyl-containing group, a carboxyl-containing group or a halogen group. Preferably, R, R' and R" are each independently the same or different and represent hydrogen, optionally branched C1-C34alkyl, C7-C34alkylaryl, C6-C34aryl, a nitro group, a carbonyl-containing group or a halogen group.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-phenylethyl)-phenyl] carbonate, 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. 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-phenylethyl)-phenyl] carbonate, bis(2-benzoylphenyl carbonate), bis(phenylsalicyl) carbonate and / or bis(benzylsalicyl) 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. Particularly preferably, the at least one diaryl carbonate is diphenyl carbonate.

[0072] 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 pK B value of at most 5.

[0073] 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, tetramethylammonium fluoride, tetramethylammonium tetraphenylboranate, tetraphenylphosphonium fluoride, tetraphenylphosphonium tetraphenylboranate, dimethyldiphenylammonium hydroxide, tetraethylammonium hydroxide, cethyltrimethylammonium tetraphenylboranate, cethyltrimethylammonium phenolate, diazabicycloundecene (DBU), diazabicylonones (DBN), 1,5,7-triazabicyclo-[4,4,0]-dec-5-ene, 7-phenyl-1,5,7-triazabicyclo-[4,4,0]-dec-5-ene, 7-methyl-1,5,7-triazabicyclo-[4,4,0]-dec-5-ene, 7,7'-hexylidenedi-1,5,7-triazabi-cyclo-[4,4,0]-dec-5-ene, 7,7'-Decylidenedi-1,5,7-triazabicyclo-[4,4,0]-dec-5-ene, 7,7'-Dodecylidene-di-1,5,7-tri-aza-bicyclo-[4,4,0]-dec-5-ene, the phosphazene base P1-t-Oct (tert-octyl-imino-tris-(dimethylamino)-phosphorane), the phosphazene base P1-t-butyl (tert-butyl-imino-tris-(dimethylamino)-phosphorane), and 2-tert-butylimino-2-diethylamino-1,3-dimethyl-perhydro-1,3,2-diaza-2-phosphorane (BEMP). Any mixtures can also be used.

[0074] Particularly preferably, the at least one catalyst 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 offer the particular advantage that they can be separated in process step (ii) according to the invention, along with the chemical compound eliminated during the condensation, for example, by vacuum. This means that the resulting polyester carbonate contains only a low catalyst content or no catalyst at all. This offers the particular advantage that no inorganic salts, which are always obtained, for example, via a route using phosgene, are present in the polymer. It is known that such salts can negatively influence the stability of the polyester carbonate, since the ions can have a catalytic effect upon corresponding degradation.

[0075] The at least one catalyst is preferably used in amounts of 1 to 5000 ppm, preferably 5 to 1000 ppm and particularly preferably 20 to 200 ppm, based on 1 mole of the cycloaliphatic dicarboxylic acid.

[0076] 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 / or one second catalyst and the condensation in process step (ii) is carried out at least in the presence of the first catalyst and the second catalyst, wherein the first catalyst is at least one tertiary nitrogen base, the second catalyst is at least one basic compound, preferably a basic alkali metal salt, and wherein the proportion of alkali metal cations in process step (ii) is 0.0008 to 0.0050% by weight, based on all components used in process step (i).

[0077] Thus, in this embodiment, a first catalyst and / or a second catalyst is present in process step (i).

[0078] The first catalyst is a tertiary nitrogen base. This first catalyst is preferably selected from guanidine-derived bases, 4-dimethylaminopyridine (DMAP), 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, hexamethylphosphorimide triamide, 1,2-dimethyl-1,4,5,6-tetrahydropyridine, 7-methyl-1,5,7-triazabicyclodec-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), DBN, ethylimidazole, N,N-diisopropylethylamine (Hünig's base), pyridine, TMG, and mixtures of these substances. More preferably, the first catalyst is selected from guanidine-derived bases, 4-dimethylaminopyridine (DMAP), 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene. 4-Dimethylaminopyridine is particularly preferred.

[0079] The first catalyst is preferably used in an amount of 0.002 to 0.10 wt.%, more preferably in an amount of 0.005 to 0.050 wt.%, particularly preferably in an amount of 0.008 to 0.030 wt.%, in each case based on all components used in process step (i).

[0080] It is preferred that the second catalyst is 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 (ii) are lithium cations, potassium cations, sodium cations, cesium cations, and mixtures thereof.

[0081] 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.

[0082] 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.

[0083] Furthermore, corresponding salts of phenols, especially phenol, can be used. These salts can be used individually or in mixtures.

[0084] 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 acetylcetonate. Lithium chloride is preferably used as an aqueous solution, for example, in the form of a 15% solution.

[0085] It has been found that the molar ratio of all aliphatic dihydroxy compounds present in process step (i) to all cycloaliphatic dicarboxylic acids present in process step (i) before the reaction in process step (i) is preferably 1:0.6 to 1:0.05, more preferably 1:0.5 to 1:0.15 and most preferably 1:0.4 to 1:0.2.

[0086] Preferably, the ratio of aliphatic dihydroxy compounds to cycloaliphatic dicarboxylic acids in the final polyester carbonate should not be too high (i.e., not too few cycloaliphatic dicarboxylic acids should be incorporated) in order to achieve particularly favorable mechanical properties, good chemical resistance, and good processing properties. Polymers with a high content of units derived from dihydroxy compounds, such as isosorbide, are usually very rigid and therefore have inadequate mechanical properties. If the content of units derived from cycloaliphatic dicarboxylic acids is too low, the processability of the polymers also deteriorates. In addition, the polyester units generally lead to better chemical resistance of the polyester carbonate, which is why the content of units derived from cycloaliphatic dicarboxylic acids should not be too low either.

[0087] According to the invention, it is particularly preferred that the molar ratio of all aliphatic dihydroxy compounds present in process step (i) to all cycloaliphatic dicarboxylic acids present in process step (i) before the reaction in process step (i) is 1:0.6 to 1:0.05, preferably 1:0.55 to 1:0.1, particularly preferably 1:0.5 to 1:0.15. It has been found according to the invention that, particularly in this range, the molecular weight buildup and thus the surface renewal are particularly good.

[0088] According to the invention, it is particularly advantageous if in the process according to the invention 60 to 90 parts of isosorbide, preferably 65 - 85 parts of isosorbide or isosorbide isomer 40 to 10 parts of cycloaliphatic dicarboxylic acid, preferably 35 - 15 parts of cycloaliphatic dicarboxylic acid, preferably 1,4-cyclohexanedicarboxylic acid 2 to 25 mol%, preferably 3 to 20 mol%, particularly preferably 4 to 18 mol% of isosorbide is replaced by the at least one further aliphatic diol, in particular a linear, very preferably branched diol having 2 to 10 carbon atoms. The total amount of the at least one aliphatic diol in the overall composition is preferably less than 20 mol%, in particular less than 15 mol%.

[0089] The process according to the invention is characterized in that carbon dioxide is released during the process. According to the invention, carbon dioxide is preferably split off in process step (i) (see reaction scheme above). This procedure allows for a rapid reaction under low temperature stress.

[0090] Furthermore, the process step (i) according to the invention preferably comprises at least one, particularly preferably all of the following steps (ia) to (ic): (ia) Melting all components present in process step (i), i.e., at least the at least one cycloaliphatic dicarboxylic acid, the at least one diaryl carbonate, and at least components (A) and (B), 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 those skilled in the art. According to the invention, the term "solvent" preferably refers to a compound that does not undergo a chemical reaction in any of process steps (i) and (ii). Excluded are those compounds 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. (ib) Heating the mixture, preferably the melt obtained from step (ia). Steps (ia) and (ib) can 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. (ic) Reaction of the mixture, preferably the mixture obtained from step (ib), with the introduction of mixing energy, preferably by stirring. Here, too, step (ic) can overlap with step (ib), since the reaction of the mixture can already be initiated by heating. The melt is preferably already heated to temperatures between 150 and 180°C under atmospheric pressure by step (ib). Depending on the catalyst selected, the temperature can be maintained in the range 160-200°C.Alternatively, the temperature in step (ic) is increased stepwise - 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 those 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. Higher temperatures are therefore less preferred. Stirring is continued under atmospheric pressure until gas evolution essentially stops. 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 (e.g. phenol when using diphenyl carbonate) is already partially removed.

[0091] It was also observed according to the invention that at least one of the dihydroxy compounds (A) and / or (B) had also already undergone reactions at this time. Thus, oligomers comprising carbonate units from the reaction of at least one of the dihydroxy compounds (A) and / or (B) with the at least one diaryl carbonate and / or ester units from the reaction of at least one of the dihydroxy compounds (A) and / or (B) with the at least one dicarboxylic acid were detected.

[0092] Therefore, it is preferred according to the invention that the mixture obtained from process step (i) comprises, before carrying out process step (ii), oligomers comprising carbonate units from the reaction of at least one of the dihydroxy compounds (component (A) and / or (B)) with the at least one diaryl carbonate and / or ester units from the reaction of at least one of the dihydroxy compounds (component (A) and / or (B)).

[0093] The reaction time in step (ic) depends on the amount of feedstock. 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 choose the reaction time such that gas evolution has substantially subsided (see reaction scheme above).

[0094] According to the invention, it is preferred that the molar ratio of the sum of all dihydroxy compounds present in process step (i) and all cycloaliphatic dicarboxylic acids present in process step (i) to all diaryl carbonates present in process step (i) before the reaction in process step (i) is 1:0.4 to 1:1.6, preferably 1:0.5 to 1:1.5, further preferably 1:0.6 to 1:1.4, particularly preferably 1:0.7 to 1:1.3, especially preferably 1:0.8 to 1:1.2, and very particularly preferably 1:0.9 to 1:1.1. The person skilled in the art is able to select appropriate, optimally suitable ratios depending on the purity of the starting substances. Process step (ii)

[0095] In process step (ii), the mixture obtained from process step (i) is further condensed, at least with removal of the chemical compound eliminated during the 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 cycloaliphatic dicarboxylic acid with the at least one diaryl carbonate, with elimination of an aryl alcohol. Preferably, however, further condensation to form oligomers has also already taken place (see process step (i)).

[0096] If only the first catalyst or only the second catalyst was used in process step (i), the catalyst not used in process step (i) is added in process step (ii).

[0097] The proportion of alkali metal cations in process step (ii) is preferably 0.0009 to 0.0005 wt.% and particularly preferably 0.0010 to 0.0045 wt.%, in each case based on all components used in process step (i).

[0098] In a preferred embodiment, the first catalyst and the second catalyst are present in process step (i).

[0099] 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 (ii).

[0100] However, the total amount of the first and / or the second catalyst is preferably used in process step (i). Most preferably, the total amount of both catalysts is used in process step (i).

[0101] The term "condensation" is familiar to those skilled in the art. It is preferably understood as 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 (ii). It is preferred that the chemical compound split off during the condensation is removed in process step (ii) by means of a vacuum. Accordingly, it is preferred that the process according to the invention is characterized in that, during the reaction in process step (i), the volatile constituents which have a boiling point below that of the cycloaliphatic diester formed in process step (i), of the mixture of dihydroxy compounds, and below that of the at least one diaryl carbonate are separated off, optionally with a gradual reduction in pressure.A stepwise separation is preferred when different volatile components are to be separated. A stepwise separation is also preferred to ensure the most complete separation of the volatile component(s). The volatile components are the chemical compound(s) released during the condensation.

[0102] 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.

[0103] The separation of the condensation product in process step (ii) preferably takes place at temperatures of 200°C to 280°C, more preferably 210°C to 260°C, and especially preferably 220°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.

[0104] The polyester carbonate according to the invention can be processed as such into moldings of all kinds. It can also be processed with other thermoplastics and / or polymer additives to form thermoplastic molding compositions. The molding compositions and moldings are further objects of the present invention.

[0105] The polymer additives are preferably selected from the group consisting of flame retardants, anti-drip agents, flame retardant synergists, smoke inhibitors, lubricants and mold release agents, nucleating agents, antistatic agents, conductivity additives, stabilizers (e.g. hydrolysis, heat aging and UV stabilizers as well as transesterification inhibitors), flow promoters, phase compatibilizers, dyes and pigments, impact modifiers as well as fillers and reinforcing agents.

[0106] The thermoplastic molding compounds can be produced, for example, by mixing the polyester carbonate and the other components in a known manner and melt compounding and melt extruding them at temperatures of preferably 200°C to 320°C in conventional equipment such as internal kneaders, extruders, and twin-screw extruders. This process is generally referred to as compounding in the context of this application.

[0107] The term molding compound is therefore understood to mean the product that is obtained when the components of the composition are melt compounded and melt extruded.

[0108] The molded articles made from the polyester carbonate of the invention or from thermoplastic molding compounds containing the polyester carbonate can be produced, for example, by injection molding, extrusion, and blow molding. Another processing method is the production of molded articles by deep drawing from previously produced sheets or films. Examples Materials used:

[0109] Cyclohexanedicarboxylic acid: 1,4-Cyclohexanedicarboxylic acid; CAS 1076-97-7 99%; Tokyo Chemical Industries, Japan, abbreviated as CHDA. According to elemental analysis, the CHDA contained less than 1 ppm of sodium. Diphenyl carbonate: Diphenyl carbonate, 99.5%, CAS 102-09-0; Acros Organics, Geel, Belgium, abbreviated as DPC 4-Dimethylaminopyridine: 4-(Dimethylaminopyridine; ≥98.0%; purum; CAS 1122-58-3; Sigma-Aldrich, Munich Germany, abbreviated as DMAP Isosorbide: Isosorbide (CAS: 652-67-5), 99.8%, Polysorb PS A; Roquette Freres (62136 Lestrem, France); abbreviated as ISB Lithium hydroxide monohydrate (CAS: 1310-66-3); >99.0%; Sigma-Aldrich 2-Butyl-2-ethyl-1,3-propanediol: CAS No.: 115-84-4; Aldrich (abbreviated as BEPD) 2,2,4,4-Tetramethyl-1,3-cyclobutanediol: , 98% (CAS: 3010-96-6); ABCR (abbreviated as TMCBD) 2,2,4-Trimethyl-1,3-pentanediol; CAS No.: 144-19-4 ; Aldrich (abbreviated as TMPD) Neopentyl glycol (2,2-dimethylpropane-1,3-diol); CAS: 126-30-7; Aldrich (abbreviated as NPG) 1,4-Butanediol: CAS: 110-63-4; Merck 99%; (abbreviated as BDO) 1,4-Cyclohexanedimethanol: CAS: 105-08-8, Aldrich 99% (abbreviated as CHDM) 1,12-Dodecanediol: CAS: 5675-51-4, Aldrich 99% (abbreviated as DDD) . Analytical methods: Solution viscosity

[0110] The relative solution viscosity (ηrel; 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. Determination of the glass transition temperature.

[0111] The glass transition temperature was determined using 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 the glass transition temperature (Tg) measured as the inflection point during the second heating process. Tensile tests

[0112] The product was dissolved in dichloromethane and neutralized with approximately 50 mg of phosphonic acid (in aq.). After homogenization, the dichloromethane was evaporated in ambient air, and the residue was removed at approximately 60°C in a vacuum drying oven under the best possible vacuum. A hand-lever grinder and a Retsch mill with a 1.5 mm sieve size were used for the subsequent mechanical comminution. Pre-drying took place at 70°C and <50 mbar in a vacuum drying oven for approximately 16 hours. The temperature was then increased to 110°C, and drying continued for 5 hours.

[0113] For the tensile tests, the films produced in the melt press were cut into 5 mm wide strips with a length of at least 50 mm. The tensile test was carried out in accordance with ASTM D 638. The strips were drawn at a room temperature of approximately 25 °C and a relative humidity of approximately 20%. The tensile modulus was determined at a preload of 0.01 MPa and a test speed of 100 mm / min. The test speed of the ongoing measurement was 50 mm / min. The strain rate was switched from 100 mm / min to 50 mm / min via the crosshead travel in a position-controlled manner. The clamping length was 20 mm. No clamp breakage was observed. The results of the tensile tests are summarized as average values ​​from five individual measurements.

[0114] The flow behavior is determined by determining the melt viscosity using a plate-on-plate viscometer according to ISO 6721-10 from 1999. The viscosity value at 1 Herz and at 10 Herz is used. The melt viscosities were determined using an Ares G-2 rotational rheometer from TA Instruments (New Castle, DE 19720, USA). A plate-on-plate geometry (25 mm diameter) was used. The plate diameter is 25 mm (PP25). The samples, in the case of evaporation residues, were first dried in a vacuum drying oven at approximately 80°C and then pressed into thin films using a hot press at 240°C. The samples were measured at various temperatures above the glass transition temperature. The deformation during the measurement was selected so that the measurement was carried out in the linear elastic range.The measurement results at the different temperatures were subsequently shifted to a master curve at the reference temperature of 200°C using time-temperature superposition. Comparative example 1 (test without additional diol)

[0115] 17.20 g (0.10 mol) of 1,4-cyclohexanedicarboxylic acid and 29.83 g (0.204 mol) of isosorbide, as well as 64.30 g (0.3 mol) of diphenyl carbonate, 0.0111 g of DMAP (4-dimethylaminopyridine; 100 ppm based on the starting materials CHDA, DPC, and ISB), and 115 µl of an aqueous solution of lithium hydroxide (100 g / l), corresponding to approximately 30 ppm Li, were placed in a flask equipped with a short-path separator. The mixture was freed of oxygen by evacuating four times and venting with nitrogen. The mixture was melted and heated to 160 °C at atmospheric pressure with stirring. The mixture was stirred for 40 minutes at 160°C, for 60 minutes at 175°C, for 30 minutes at 190°C, and for 10 minutes at 205°C. Carbon dioxide evolved continuously. After CO2 evolution ceased, the bath temperature was adjusted to 220°C. After another 20 minutes, a vacuum was applied. The pressure was reduced to 10 mbar over 30 minutes, while phenol was continuously removed.The mixture was stirred at 10 mbar for approximately 10 minutes. The pressure was then reduced to <1 mbar (approximately 0.7 mbar) and condensed for another 10 minutes. The reaction was then stopped.

[0116] A light yellow polymer with a solution viscosity of eta rel 1.33 was obtained

[0117] The other examples (Ex.) and comparative examples (Cf.) were carried out as described for Comparative Example 1. In contrast to Example 1, the aliphatic diols listed in Table 1 were additionally introduced into the flask equipped with a short-path separator along with all other monomers forming the polymer and the catalyst. Table 1: See 1 Experience 1 Experience 2 Experience 3 Experience 4 Experience 5 Experience 6 Experience 7 Experience 8 Experience 9 See.. 2 See 3 See 4 See 5 See 6 See 7 Molar ratio CHDA / ISB / HO-R-OH 33 / 67 / 0 33 / 64 / 3 33 / 60 / 7 33 / 57 / 10 33 / 64 / 3 33 / 57 / 10 33 / 60 / 7 33 / 64 / 3 33 / 64 / 3 33 / 57 / 10 33 / 64 / 3 33 / 64 / 3 33 / 57 / 10 33 / 33,5 / 33,5 33 / 33,5 / 33,5 33 / 33,5 / 3 3,5 mol-% HO-R-OH 0 5 10 15 5 15 10 5 5 15 5 5 15 50 50 50 CHDA (mol) approx. 0,1 0,2 0,2 0,2 0,2 0,2 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 HO-R-OH approx. (mol) 0 0.02 TMPD 0.04 TMPD 0.06 TMPD 0.02 NPG 0.06 NPG 0.02 BEPD 0.01 BEPD 0.01 TMCB D 0.03 TMCBD 0.01 BDO 0.01 CHDM 0.03 DDD 0.1 TMPD 0.1 NPG 0.1 DDD DPC (mol) approx. 0,3 0,6 0,6 0,6 0,6 0,6 0,3 0,3 0,3 0,3 0,3 0,3 0,3 0,3 0,3 0,3 ISB (mol) approx. 0,2 0,38 0,36 0,34 0,38 0,34 0,18 0,19 0,19 0,17 0,19 0,19 0,17 0,1 0,1 0,1 Eta rel 1,33 1,383 1,362 1,647 1,413 1,446 1,501 1,474 1,434 1,606 1,396 1,41 1,301 1,094 1,119 1,149 Glass transition temperature in °C 151 144 146 138 150 147 133 142 154 153 145 145 94 94 84 gel-like at room temperature Tensile modulus (E-modulus) N / mm 2< 1740 ± 128 283 ± 64 1130 ± 183 1020 ± 55,8 1210 ± 110 917 ± 145 79,6 ± 29,3 135 ± 75,4 83,5 ± 7 258 ± 128 998 ± 88 Not measurable Not measurable Not measurable Elongation at break (DR) % 8,8 ± 0,9 8,3 ± 2,8 7,6 ± 1,5 16,7 ± 13,5 10,0 ± 1,5 8,5 ± 2,4 6,2 ± 1,2 5,7 ± 1,7 10,2 ± 3,6 7,0 ± 0,8 7,7 ± 0,6 Not measurable Not measurable Not measurable Shear viscosity at 1 Hz 27840 Pas 35920 Pas 60960 Pas Shear viscosity at 10 Hz 8160 Pas 7760 Pas 15470 Pas

[0118] The mole values ​​in the first column of Table 1 are indicated with "approx." because they were rounded to two decimal places. The ratio used was 2.04:1.00 (diols to diacids).

[0119] Inventive examples 1 to 9 demonstrate that the inventive process yields the desired polyester carbonates in high viscosities as long as the inventive amounts of additional diol are maintained. It can be seen that the addition of an additional aliphatic, branched diol significantly increases the molecular weight compared to an example in which no additional aliphatic diol is present (see Comparative Example 1). Improved miscibility was observed at higher temperatures, allowing a further increase in molecular weight. If too high an amount of additional diol is used (see Comparative Examples 5 to 7), the increase in molecular weight is significantly lower.Furthermore, it can be seen that the presence of a structural unit (B) in the polyester carbonate initially reduces the mechanical properties, such as Young's modulus and elongation at break, but a higher molecular weight can be achieved overall. The higher the proportion of structural unit (B), the better the mechanical properties such as Young's modulus and elongation at break. However, an excessively high proportion of structural unit (B) in turn leads to a low molecular weight and thus again to a deterioration in the mechanical properties. In the inventive amount range of structural unit (B), a good balance between mechanical properties and molecular weight is thus achieved. In addition, high molecular weights lead to lower end group contents. This is advantageous in principle, since molecular weight reduction generally starts at the chain end.

[0120] It should be noted that the error values ​​for the Young's modulus and elongation at break are relatively high. This results from the relatively small sample quantities used and the fact that blistering occurred in some cases. However, it is understandable to those skilled in the art that, despite these errors, the resulting values ​​are meaningful.

[0121] It can also be seen that using additional branched diols (both branched alkylene groups and branched cycloalkylene groups) results in a lower shear viscosity despite higher solution viscosity and at comparable Tg values. 1. Polyester carbonate comprising the structural formula (1) in which A per repeating unit independently represents at least either structural unit (A) or structural unit (B), where (A) represents the chemical formula (2) and (B) represents the chemical formula (3) *-x-* (3), where x represents a branched alkylene group having 4 to 20, preferably 5 to 15 carbon atoms, which may optionally be interrupted by at least one heteroatom, or a cycloalkylene group having at least one branch, wherein the cycloalkylene group has 4 to 20, preferably 5 to 15 carbon atoms, may optionally be interrupted by at least one heteroatom, and wherein the cycloalkylene group may optionally contain several rings, y each independently represents the chemical formula (IIIa) or (IIIb) in which B each independently represents a CH 2 group or a heteroatom selected from the group consisting of O and S, preferably a CH 2 group or an oxygen atom, R 1 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, n is a number between 0 and 3, preferably 0 or 1 and 0 < x < 1 , where the * each indicate the position at which the chemical formulas are incorporated into the polyester carbonate, characterized in that the polyester carbonate comprises 98 mol% to 75 mol%, preferably 97 mol% to 80 mol%, particularly preferably 96 mol% to 82 mol% of the structural unit (A) and 2 mol% to 25 mol%, preferably 3 mol% to 20 mol%, particularly preferably 4 mol% to 18 mol% of the structural unit (B), in each case based on the sum of the structural units (A) and (B), and in that the polyester carbonate has a relative solution viscosity, measured in dichloromethane at a concentration of 5 g / l at 25 °C using an Ubbelohde viscometer, of 1.20 to 1.70, preferably 1.23 to 1.67, particularly preferably 1.25 to 1.65. 2. Polyester carbonate according to claim 1, characterized in that the polyester carbonate consists of at least 80 wt.%, preferably 85 wt.%, particularly preferably 90 wt.% of the structural formula (1), based on the total weight of the polyester carbonate.3. Polyester carbonate according to one of claims 1 or 2, characterized in that the polyester carbonate comprises the following repeating units (i) to (iv) in any order. in which a, b, c and d each independently represent a natural number which in each case indicates the average number of repeating units. 4. Polyester carbonate according to one of claims 1 to 3, characterized in that 1 mol% to 20 mol%, preferably 2 mol% to 18 mol%, particularly preferably 3 mol% to 15 mol% of the polyester carbonate consists of the structural motif *-xO-*, based on the total sum of the following structural motifs *-xO-*, 5. Polyester carbonate according to one of claims 1 to 4, characterized in that *-x-* is selected from the group consisting of 2,2-bis(4-cyclohexylene)propane, 2-butyl-2-ethyl-1,3-propylene, 2,2,4,4-tetramethyl-1,3-cyclobutylene, 2,2,4-trimethyl-1,3-pentylene, 2,2-dimethylpropan-1,3-ylene, 8-(methylene)-3-tricyclo[5.2.1.02,6]decanyl]methylene and any mixtures thereof. 6. Polyester carbonate according to one of claims 1 to 5, characterized in that y is selected from the group consisting of 1,4-cyclohexylene, 1,3-cyclohexylene, 1,2-cyclohexylene, tetradihydro-2,5-furanylene, tetradihydro-2,5-dimethylfuranylene, decahydro-2,4-naphthalenylene, decahydro-2,5-naphthalenylene, decahydro-2,6-naphthalenylene and decahydro-2,7-naphthalenylene. 7. Polyester carbonate according to one of claims 1 to 6, characterized in that the molar ratio of the sum of the structural motifs *-xO-* and to the structural motif 6:4 to 9:1. 8. Polyester carbonate according to one of claims 1 to 7, characterized in that at least 45 mol%, preferably at least 50 mol% of the polyester carbonate consists of the structural motif consists of the total sum of the following structural motifs *-xO-* 9. Molding composition containing a polyester carbonate according to one of claims 1 to 8. 10. Molded body containing a polyester carbonate according to one of claims 1 to 8. 11. Process for producing a polyester carbonate according to one of claims 1 to 8 by melt transesterification, comprising the steps (i) reaction of at least one dicarboxylic acid of the chemical formula (IIa) or (IIb) wherein B each independently represents a CH 2 group or a heteroatom selected from the group consisting of O and S, preferably a CH 2 group or an oxygen atom, R 1 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, with at least one diaryl carbonate using at least one catalyst and in the presence of a mixture of dihydroxy compounds comprising (A) at least one 1,4:3,6-dianhydrohexitol and (B) at least one further aliphatic dihydroxy compound of the chemical formula (I) HO-X-OH (I), in which X represents a branched alkylene group having 4 to 20, preferably 5 to 15 carbon atoms,which may optionally be interrupted by at least one heteroatom or a cycloalkylene group with at least one branch, wherein the cycloalkylene group has 4 to 20, preferably 5 to 15 carbon atoms, may optionally be interrupted by at least one heteroatom and wherein the cycloalkylene group may optionally contain several cycles, and (ii) further condensation of the mixture obtained from process step (i) at least with removal of the chemical compound split off during the condensation, characterized in that the mixture of dihydroxy compounds 98 mol% to 75 mol%, preferably 97 mol% to 80 mol%, particularly preferably 96 mol% to 82 mol% of component (A) and 2 mol% to 25 mol%, preferably 3 mol% to 20 mol%, particularly preferably 4 mol% to 18 mol% of component (B), in each case based on the sum of components (A) and (B). 12. The method according to claim 11, characterized in thatthat the molar ratio of all aliphatic dihydroxy compounds present in process step (i) to all cycloaliphatic dicarboxylic acids present in process step (i) before the reaction in process step (i) is 1:0.6 to 1:0.05, preferably 1:0.55 to 1:0.1, particularly preferably 1:0.5 to 1:0.15. 13. The process according to claim 11 or 12, characterized in that the at least one further aliphatic dihydroxy compound of the chemical formula (I) is selected from the group consisting of 2,2-bis(4-hydroxycyclohexyl)propane, 2-butyl-2-ethyl-1,3-propanediol, 2-(2-hydroxyethoxy)ethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2-dimethylpropane-1,3-diol, 8-(hydroxymethyl)-3-tricyclo[5.2.1.0 2,6 ]decanyl]methanol and any mixtures thereof. 14. The process according to any one of claims 11 to 13, characterized in that the at least one cycloaliphatic dicarboxylic acid 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. 15. The process according to any one of claims 11 to 14, characterized in that the at least one diaryl carbonate is selected from the group consisting of a compound of formula (2), wherein R, R' and R" may each independently be the same or different and represent hydrogen, optionally branched C1-C34alkyl, C7-C34alkylaryl, C6-C34aryl, a nitro group, a carbonyl-containing group, a carboxyl-containing group or a halogen group.

Claims

1. Polyestercarbonate, comprising the structural formula (1) in which A independently per repeating unit represents at least either structural unit (A) or structural unit (B), where (A) represents chemical formula (2) and (B) represents chemical formula (3)         *-x-*     (3), where x represents a branched alkylene group having 4 to 20, preferably 5 to 15 carbon atoms, which may optionally be interrupted by at least one heteroatom, or a cycloalkylene group comprising at least one branch, wherein the cycloalkylene group has 4 to 20, preferably 5 to 15 carbon atoms, may optionally be interrupted by at least one heteroatom and wherein the cycloalkylene group may optionally contain a plurality of rings, y each independently represents chemical formula (IIIa) or (IIIb) in which 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, R1 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, especially preferably a single bond, n is a number between 0 and 3, preferably 0 or 1, and 0 < x < 1, where the * in each case indicate the position at which the chemical formulae are incorporated into the polyestercarbonate, characterized in that the polyestercarbonate comprises 98 mol% to 75 mol%, preferably 97 mol% to 80 mol%, especially preferably 96 mol% to 82 mol%, of structural unit (A) and 2 mol% to 25 mol%, preferably 3 mol% to 20 mol%, especially preferably 4 mol% to 18 mol%, of structural unit (B), based in each case on the sum of the structural units (A) and (B), and in that the polyestercarbonate has a relative solution viscosity, measured in dichloromethane at a concentration of 5 g / l at 25°C with an Ubbelohde viscometer, of 1.20 to 1.70, preferably 1.23 to 1.67, especially preferably 1.25 to 1.65.

2. Polyestercarbonate according to Claim 1, characterized in that the polyestercarbonate consists of structural formula (1) to an extent of at least 80% by weight, preferably 85% by weight, particularly preferably 90% by weight, based on the total weight of the polyestercarbonate.

3. Polyestercarbonate according to either of Claims 1 and 2, characterized in that the polyestercarbonate comprises the following repeating units (i) to (iv) in any order in which a, b, c and d each independently represent a natural number which indicates the average number of repeating units in each case.

4. Polyestercarbonate according to any of Claims 1 to 3, characterized in that 1 mol% to 20 mol%, preferably 2 mol% to 18 mol%, especially preferably 3 mol% to 15 mol% of the polyestercarbonate consists of the structural motif *-x-Q-*, based on the total sum of the following structural motifs *-x-O-*, 5. Polyestercarbonate according to any of Claims 1 to 4, characterized in that *-x-* is selected from the group consisting of 2,2-bis(4-cyclohexylene)propane, 2-butyl-2-ethyl-1,3-propylene, 2,2,4,4-tetramethyl-1,3-cyclobutylene, 2,2,4-trimethyl-1,3-pentylene, 2,2-dimethylpropan-1,3-ylene, 8-(methylene)-3-tricyclo[5.2.1.02,6]decanyl]methylene and any desired mixtures thereof.

6. Polyestercarbonate according to any of Claims 1 to 5, characterized in that y is selected from the group consisting of 1,4-cyclohexylene, 1,3-cyclohexylene, 1,2-cyclohexylene, tetradihydro-2,5-furanylene, tetradihydro-2,5-dimethylfuranylene, decahydro-2,4-naphthalenylene, decahydro-2,5-naphthalenylene, decahydro-2,6-naphthalenylene and decahydro-2,7-naphthalenylene.

7. Polyestercarbonate according to any of Claims 1 to 6, characterized in that the molar ratio of the sum of the structural motifs *-x-O-* and to the structural motif is 6:4 to 9:1.

8. Polyestercarbonate according to any of Claims 1 to 7, characterized in that at least 45 mol%, preferably at least 50 mol% of the polyestercarbonate consists of the structural motif based on the total sum of the following structural motifs *-x-O-*, and 9. Molding compound comprising a polyestercarbonate according to any of Claims 1 to 8.

10. Molded article comprising a polyestercarbonate according to any of Claims 1 to 8.

11. Process for preparing a polyestercarbonate according to any of Claims 1 to 8 by means of melt transesterification, comprising the steps of (i) reaction at least of at least one dicarboxylic acid of chemical formula (IIa) or (IIb) where B in each case 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, R1 in each case 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, more preferably a single bond, and n is a number between 0 and 3, preferably 0 or 1, with at least one diaryl carbonate using at least one catalyst and in the presence of a mixture of dihydroxy compounds, comprising (A) at least one 1,4:3,6-dianhydrohexitol and (B) at least one further aliphatic dihydroxy compound of chemical formula (I)         HO-X-OH     (I), in which X represents a branched alkylene group having 4 to 20, preferably 5 to 15 carbon atoms, which may optionally be interrupted by at least one heteroatom, or a cycloalkylene group comprising at least one branch, wherein the cycloalkylene group has 4 to 20, preferably 5 to 15 carbon atoms, may optionally be interrupted by at least one heteroatom and wherein the cycloalkylene group may optionally contain a plurality of rings, and (ii) further condensation of the mixture obtained from process step (i), at least with removal of the chemical compound eliminated in the condensation, characterized in that the mixture of dihydroxy compounds comprises 98 mol% to 75 mol%, preferably 97 mol% to 80 mol%, especially preferably 96 mol% to 82 mol% of component (A) and 2 mol% to 25 mol%, preferably 3 mol% to 20 mol%, especially preferably 4 mol% to 18 mol% of component (B), based in each case on the sum of components (A) and (B).

12. Process according to Claim 11, characterized in that the molar ratio of all aliphatic dihydroxy compounds present in process step (i) to all cycloaliphatic dicarboxylic acids present in process step (i) prior to the reaction in process step (i) is 1:0.6 to 1:0.05, preferably 1:0.55 to 1:0.1, particularly preferably 1:0.5 to 1:0.15.

13. Process according to Claim 11 or 12, characterized in that the at least one further aliphatic dihydroxy compound of chemical formula (I) is selected from the group consisting of 2,2-bis(4-hydroxycyclohexyl)propane, 2-butyl-2-ethyl-1,3-propanediol, 2-(2-hydroxyethoxy)ethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2-dimethylpropane-1,3-diol, 8-(hydroxymethyl)-3-tricyclo[5.2.1.02,6]decanyl]methanol and any desired mixtures thereof.

14. Process according to any of Claims 11 to 13, characterized in that the at least one cycloaliphatic dicarboxylic acid 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.

15. Process according to any of Claims 11 to 14, characterized in that the at least one diaryl carbonate is selected from the group consisting of a compound of formula (2) where R, R' and R" may each independently be identical or different and represent hydrogen, optionally branched C1-C34 alkyl, C7-C34 alkylaryl, C6-C34 aryl, a nitro group, a carbonyl-containing group, a carboxyl-containing group or a halogen group.