Oligoesters containing resorcinol and isophthalic and / or terephthalic acid, corresponding polyester carbonates and their preparation

Abstract

The present invention relates to mixtures containing oligoesters, polyestercarbonates containing ester blocks, and a method for preparing polyestercarbonates having ester blocks by melt transesterification.

Description

[Technical field]

[0001] The present invention relates to mixtures comprising oligoesters, polyestercarbonates comprising ester blocks, and methods for preparing polyestercarbonates having ester blocks. [Background technology]

[0002] Aromatic polyester carbonates are known to have good properties in terms of mechanical properties and heat distortion resistance. It is also known that certain polyester carbonates, especially those containing ester blocks formed from aromatic diacids and resorcinol, have high weatherability.

[0003] In particular, polyester carbonates containing ester blocks formed from isophthalic acid and / or terephthalic acid and resorcinol are known to have good weather resistance. These materials are particularly interesting because they do not require any coating to protect them from harmful weathering effects and in particular from UV light. The ester structures formed from resorcinol and isophthalic acid and / or terephthalic acid can initiate the so-called optical Fries rearrangement when in contact with UV light. This results in the formation of hydroxybenzophenone structures incorporated within the polymer chain. It is known that hydroxybenzophenones have UV absorbing properties. This explains the good weather resistance. This subject is described, for example, in US Pat. No. 5,399,363. In contrast, the alternative use of UV absorbers is extremely ineffective, since most of the UV absorbers accumulate in the bulk. The concentration of UV absorbers, especially at the surface to be protected against UV light, is relatively low. If the skilled person wishes to use higher concentrations of UV absorbers, further drawbacks are encountered. For example, low molecular weight compounds, especially at relatively high concentrations, reduce the mechanical properties. This is undesirable. In order to fix a relatively high concentration of UV absorber on the surface, it is customary to protect UV-sensitive materials such as polycarbonate with a coating layer containing a high concentration of UV absorber. However, coating is an additional step that is costly and is not always a preferred solution for sustainability reasons. Especially in the field of automotive applications, it is advantageous if the material is inherently weather-stable and can omit the labor-intensive coating.

[0004] The described polyester carbonates are prepared in the prior art by an interfacial process, in which aromatic diols and OH-terminated ester blocks are incorporated by condensation with phosgene. The OH-terminated ester blocks can likewise be prepared in solution by condensation with phosgene starting from aromatic diacids and aromatic diols. Such a method for preparing oligoesters and the corresponding polyester carbonates is described in US Pat. No. 5,399,433. This document describes polyester carbonates formed from bisphenol A-containing ester blocks formed from terephthalic / isophthalic acid as preferred polymers. Here, the ester blocks are prepared in a dichloromethane / water mixture starting from acid chlorides of aromatic diacids and resorcinol using aqueous NaOH. The polyester solution containing the hydroxy-terminated ester blocks is transferred to a phosgenation reactor. If preferred, an alkaline bisphenol A solution is introduced and the reactants are reacted with phosgene.

[0005] Processes based on the melt transesterification process known for polycarbonates are known, and have the advantage of avoiding difficult-to-handle feedstocks, such as phosgene. In addition, this has the great advantage of making it possible to dispense with the consumption of solvents. It would therefore be industrially advantageous to prepare polyestercarbonates by the melt transesterification process. However, this process also has its challenges. For example, it is always difficult to replace highly reactive acid chlorides with other feedstocks. The transesterification process often involves long residence times in the corresponding reactor. The high temperatures often produce decomposition products that adversely affect the quality of the product. The melt transesterification process does not usually require complex post-treatment steps, so impurities, including catalyst residues, remain in the product. These can deteriorate the quality of the product.

[0006] Moreover, polycarbonates prepared by the melt transesterification process will have a significantly higher content of hydroxy-terminated end groups (phenolic OH group content) compared to the corresponding products from the interfacial process. These phenolic OH groups can be damaged by the oxidation process, which deteriorates the quality of the product. This affects in particular the optical properties. However, it is important to obtain good optical properties, especially for products characterized by high inherent weatherability. It is therefore advantageous if the phenolic OH end group content is low. However, in this regard, the prior art does not teach anything about the polyester carbonates mentioned, since the prior art is only concerned with the preparation of polyester carbonates by interfacial reactions. Therefore, the skilled person does not know how such polyester carbonates with low OH end group content should be prepared by the melt transesterification process.

[0007] For the above reasons, it is also not known how such polyestercarbonates can be prepared with high viscosity or molecular weight due to the lower reactivity of the reactants compared to the feedstocks in the interfacial process.

[0008] US Pat. No. 5,399,633 describes the preparation of hydroxy-terminated oligoester blocks in the melt. The question is how to achieve an OH end group content of the oligoesters comparable to those obtainable by solvent-based processes. For this purpose, the effect of different catalysts and operating modes (e.g., different temperatures and vacuums) was also tested. The resulting molecular weight of the oligoesters is relatively low. Although oligoesters with phenoxy end groups are described here, US Pat. No. 5,399,633 does not describe any molecular weight distribution of the oligomers of the oligoesters. Moreover, the oligoesters are subsequently incorporated by condensation by an interfacial process to obtain polyestercarbonates. This document therefore does not contain any teaching on how end groups and / or oligomer distribution affect the preparation of polyestercarbonates by melt transesterification.

[0009] In Patent Document 4, oligoesters are prepared by melt transesterification process, which are characterized by having a high percentage of carboxyl end groups. These carboxyl end groups are then utilized to incorporate the oligoesters into coating systems. However, free acids are relatively unreactive in the melt transesterification process for preparing polyester carbonates, and therefore these precursors are not suitable for the above-mentioned melt-based polyester carbonates. Therefore, it does not describe their use in the melt transesterification process.

[0010] US Patent No. 5,399,663 describes the preparation of oligomers from aromatic diacids and resorcinol. The problem solved by US Patent No. 5,399,663 is to provide OH-terminated units that can then be converted into polyester carbonates by interfacial processes. As in US Patent No. 5,399,663, the oligomer distribution, end group ratio, or its effect on the melt transesterification of oligoesters is not addressed here. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] U.S. Patent Application Publication No. 20030050400 [Patent Document 2] International Publication No. 0026275 [Patent Document 3] International Publication No. 2005021616 [Patent Document 4] International Publication No. 2006057810 Summary of the Invention [Problem to be solved by the invention]

[0012] Starting from this prior art, the problem addressed by the present invention was to overcome at least one of the drawbacks of the prior art. More specifically, the problem addressed by the present invention was to provide polyester carbonates comprising ester blocks based on isophthalic acid and / or terephthalic acid and resorcinol, which can be obtained by a melt transesterification process. What should be obtained here is preferably a polyester carbonate that has good processability and at the same time has a minimum content of phenolic OH end groups. Thus, the polyester carbonates should preferably be weather-stable and / or otherwise substantially yellowing-stable and / or have substantially no tendency to polymer degradation, for example by oxidative degradation. It is also preferred that no raw materials that are difficult to handle, such as phosgene, are used in the preparation of the polyester carbonates. [Means for solving the problem]

[0013] At least one, preferably all of the above problems have been solved by the present invention. Surprisingly, it has been found that processable polyestercarbonates can be provided via melt transesterification only if the oligoesters have a defined end group content and a defined proportion of small oligomers. Only if mixtures containing 0.5% by weight or less of oligoesters with OH end groups, such as phenolic OH end groups, are used (where the groups in the end groups are essentially specific aromatic groups, preferably phenyl), and the proportion of oligomers with a molecular weight of less than 1000 g / mol is low, polyestercarbonates with high molecular weights (but not too high) and at the same time a sufficiently low content of phenolic OH end groups, so that the polyestercarbonates have high stability, for example against degradation, can be obtained by melt transesterification. The effect of using specific polyestercarbonates is that novel polyestercarbonates are obtained in which isophthalic and / or terephthalic acid groups are highly directly bonded to the carbonate blocks. In the prior art, oligoesters are used with a maximum OH end group content. The effect of this is that the diols used (e.g. resorcinol) automatically form the end groups of these oligoesters. These are then bonded to the carbonate blocks, resulting in, for example, carbonate-resorcinol bonds. In contrast, the oligoesters according to the invention are essentially terminated with specific aromatic esters of isophthalic acid and / or terephthalic acid. The effect of this is that the polyestercarbonates have a novel bond via isophthalic acid and / or terephthalic acid. By providing specific oligoesters, it is possible to obtain polyestercarbonates from oligocarbonate and oligoester blocks by melt transesterification, which have good properties with respect to the above-mentioned desired objectives.

[0014] The present invention therefore relates to a mixture comprising an oligoester of formula (1), [ka] During the ceremony, Each R1 are independently a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, each q is independently 0 or 1; When q=1: each Z is independently —H or an aromatic group of formula (2a); [ka] In the formula, R 2 ' is hydrogen or -COOCH 3 where "*" indicates the position where formula (2a) is bonded to the oxygen atom in formula (1), When q=0: each Z is independently an aromatic group of formula (2), [ka] In the formula, R 2 is hydrogen or -COOCH 3 where "*" indicates the position where formula (2) is bonded to the oxygen atom in formula (1), p indicates the number of repeating units, In the mixture, no more than 0.5% by weight of the Z groups for the mixture are hydrogen, and the percentage of oligomers in the mixture having a molecular weight less than 1000 g / mol is less than 12%, preferably less than 10%, where the percentage of oligomers is determined by the ratio of the area under the molecular weight distribution curve of the mixture for refractive index signals (from gel permeation chromatography) in the range less than 1000 g / mol to the total area under the molecular weight distribution curve, where the gel permeation chromatography is performed in dichloromethane using bisphenol A polycarbonate standards; The present invention provides a mixture comprising:

[0015] According to the invention, the expression "mixture comprising oligoesters of formula (1)" should be understood such that the mixture essentially consists of oligoesters of formula (1). This means that preferably at least 80% by weight of the mixture, more preferably at least 90% by weight, most preferably at least 95% by weight, consists of oligoesters of formula (1). However, it cannot be excluded that, as a result of the preparation, the mixture also contains a certain proportion of oligoesters having formula (1), but in which at least one q is 0, in which case Z at the chain end of the oligoester with q=0 is hydrogen. In this case, R 1 and p has the above definition. This means that the oligoester is terminated on at least one side with isophthalic / terephthalic acid (-COOH as the end group).

[0016] If oligoesters of formula (1) are present in the mixture according to the invention, in which at least one q is 0 and Z at this chain end of the oligoester with q=0 is hydrogen, these OH end groups (-COOH end groups) are not included in the defined weight percentage of the OH end groups (via Z in formula (1)) in the mixture according to the invention. Preferably, the proportion of -COOH end groups in the mixture according to the invention (via Z at the chain end of at least one oligoester with q=0 and Z at this chain end of the oligoester with q=0 in formula (1) is hydrogen) is not more than 10% by weight, more preferably not more than 8% by weight, even more preferably not more than 5% by weight, most preferably not more than 2% by weight, relative to the total weight of the mixture. The skilled person knows how these -COOH end groups can be determined. In particular, the proportion of -COOH end groups in the mixture according to the invention (via Z at the chain end of the oligoester with q=0 and Z at this chain end of the oligoester with q=0 in formula (1) is hydrogen) is not more than 10% by weight, more preferably not more than 8% by weight, even more preferably not more than 5% by weight, most preferably not more than 2% by weight, relative to the total weight of the mixture. 13By NMR measurements, the carbon atoms which are part of the acid end groups can be determined. For this purpose, deuterated DMSO is a particularly suitable solvent. The carbon atoms which are part of the acid end groups should usually be in the range of 160 ppm to 170 ppm, in particular 163 ppm to 169 ppm. According to the invention, it is preferred that the content of formula (1) in the mixture according to the invention is low, in which at least one q is 0 and Z is hydrogen at the chain end of the oligoester with q=0.

[0017] According to the invention, the mixture contains in total not more than 0.5% by weight, preferably not more than 0.45% by weight, more preferably not more than 0.4% by weight, most preferably not more than 0.35% by weight of OH end groups, based on the total weight of the mixture (preferably 1 1 H NMR) is preferred.

[0018] Preferably, R in formula (1) 1 is hydrogen. This means that R 1 This means that the ring substituted by is preferably derived from resorcinol.

[0019] Preferably, R in formula (2) 2 is hydrogen. This can be combined with formula (1) to give formula (2) R 2 is preferably phenyl isophthalate and / or terephthalate.

[0020] Also preferably, R in formula (2a) 2 ' is hydrogen. This, in combination with formula (1), gives R 2 ' means that the group present is preferably resorcinol phenyl carbonate.

[0021] Particularly preferably, R 1 is hydrogen, and R in formula (2) 2 is hydrogen, and R in formula (2a) 2 ' is hydrogen.

[0022] In formula (1), p denotes the number of repeating units of the oligoester. p preferably has an average value of at least 4. More preferably, p in formula (1) has an average value of at least 4 and at most 30, more preferably at least 5 and at most 27, most preferably at least 5 and at most 24. It is particularly preferred that the mixture of oligoesters has a number average molar mass in the range of 1300 g / mol to 6000 g / mol, more preferably 1400 g / mol to 5500 g / mol, most preferably 1500 g / mol to 5000 g / mol. This M n is preferably determined by gel permeation chromatography in dichloromethane using bisphenol A polycarbonate as standard. The molecular weights Mw (weight average) and Mn (number average) for the oligoester or polyester carbonates used according to the invention were determined by size exclusion chromatography (gel permeation chromatography, GPC; according to DIN 55672-1:2007-08 using BPA polycarbonate calibration), unless otherwise stated. Calibration was carried out using linear polycarbonates of known molar mass distribution (e.g. from PSS Polymer Standards Service GmbH, Germany). This was carried out using method 2301-0257502-09D (German from 2009) from Currenta GmbH & Co. OHG, Leverkusen. Dichloromethane was used as eluent. The column combination consisted of crosslinked styrene-divinylbenzene resin. GPC is used to characterize polymers, in particular those with weight-average molar masses M w The analytical column may comprise one or more serially connected commercially available GPC columns for size exclusion chromatography, selected to provide sufficient separation of the molar masses of aromatic polycarbonates having the following properties: The analytical column typically has a diameter of 7.5 mm and a length of 300 mm. The particle size of the column material ranges from 3 μm to 20 μm.

[0023] The mixture according to the present invention is a compound represented by the formula (1) 1is hydrogen, not more than 0.4% by weight of the Z groups for the mixture are hydrogen, and the percentage of oligomers having a molecular weight below 1000 g / mol is less than 10%.

[0024] The mixture according to the invention has at most 0.5% by weight, preferably at most 0.45% by weight, more preferably at most 0.4% by weight, most preferably at most 0.35% by weight of OH end groups (meaning that Z in formula (1) is hydrogen), based on the total mixture. This OH end group content can be determined by methods known to those skilled in the art. The OH end group content is preferably 1 It can be determined by H NMR. This can be done, for example, in dichloromethane with tetramethylsiloxane as internal standard. For this purpose, the area under the signal of the OH group (which is usually located at 5.3 ppm to 5.6 ppm) can be expressed relative to the area of ​​the other signals of the oligomer.

[0025] Surprisingly, it has been found that, if the OH end group content of the mixture according to the invention is more than 0.5% based on the total mixture, this mixture of oligoesters has such a high reactivity that polyestercarbonates are obtained by melt transesterification with a relative solution viscosity that is no longer processable (i.e. usually above 1.35 eta rel). That is to say, what is obtained are polyestercarbonates that are always difficult to process, for example to obtain molded articles by injection molding. At the same time, many of these polyestercarbonates obtained in this way also have a phenolic OH content. This usually leads to unstable polymers that are prone to degradation by temperature and / or light. In contrast, if the OH end group content of the mixture according to the invention is less than or equal to 0.5% by weight based on the total mixture, taking into account its molecular weight (measured as eta rel) and its resulting phenolic OH end group content, polyestercarbonates can be obtained that not only have good processability (for example by injection molding), but are also very stable against degradation.

[0026] According to the invention, it is preferred that, relative to formula (1), the ratio of end groups in which Z corresponds to formula (2a) and / or formula (2) to end groups in which Z is hydrogen (and in which q=1) is from 10:1 to 2:1, more preferably from 9:1 to 3:1, most preferably from 8:1 to 4:1. This end group ratio can be determined by methods known to those skilled in the art. In particular, this ratio is 1 It can be determined by H NMR, preferably at least at 700 MHz. This can be done, for example, in dichloromethane with tetramethylsiloxane as internal standard. For this purpose, the area under the signal of the OH group (which is usually at 5.3 ppm to 5.6 ppm) can be expressed relative to the area of ​​the other signals of the oligomer. Depending on the overlap of peaks and the choice of monomers forming the oligoester according to the invention, it is also possible to express, for example, the area of ​​the peak at about 7.4 ppm, which should correspond to the phenyl end group (2 protons), relative to the area of ​​the peak at 6.6 ppm to 6.8 ppm, which should correspond to the resorcinol end group (3 protons).

[0027] It was likewise surprisingly found that in order to obtain a sufficient increase in the molecular weight of the polyestercarbonate by melt transesterification, the proportion of oligomers in the mixture according to the invention with a molecular weight of less than 1000 g / mol must be less than 12%, preferably less than 11%, more preferably less than 10%. If the proportion is more than 12%, the mixture of oligoesters will not be sufficiently reactive to obtain a sufficient increase in molecular weight. This means that the polyestercarbonate obtained will not have the desired properties in terms of processability, mechanical properties and optical properties. According to the invention, the proportion of oligomers with a molecular weight of less than 1000 g / mol is determined by the ratio of the area under the molecular weight distribution curve of the mixture for the refractive index signal (from gel permeation chromatography) in the range of less than 1000 g / mol to the total area under the molecular weight distribution curve. Here, gel permeation chromatography is carried out in dichloromethane with a bisphenol A polycarbonate standard (see also the precise description of gel permeation chromatography above). The curve of the refractive index signal versus molecular weight can be integrated by methods known to those skilled in the art, in particular by GPC software. The area under the curve below 1000 g / mol is expressed here relative to the total area. It will be clear that the Mn of the mixture of oligoesters will affect the amount of oligomers with a molecular weight below 1000 g / mol. This means, firstly, that if the Mn value of the oligoester is low, there will be a relatively narrow distribution of molecular weight distribution, in which the proportion of oligomers with a molecular weight below 1000 g / mol is less than 12%. However, secondly, this can also mean that the oligoester preferably has a relatively high Mn, and therefore the proportion of oligomers with a molecular weight below 1000 g / mol is less than 12%.

[0028] The mixtures according to the invention comprising oligoesters of formula (1) in all the above-mentioned preferred and preferred combinations are (i) at least isophthalic acid and / or terephthalic acid are mixed with a diol of formula (3) and at least one diaryl carbonate of formula (4), [ka] In the formula, R 1 is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, preferably a hydrogen atom; [ka] In the formula, R 2 is, independently in each occurrence, hydrogen or -COOCH 3 , preferably hydrogen; (ii) the mixture from step (i) is heated in the presence of at least one catalyst; (iii) applying a reduced pressure to the mixture from step (ii) to obtain a mixture comprising an oligoester. It is preferably manufactured via a process.

[0029] Optionally, this process according to the invention can also be supplemented by step (iv), in which the mixture containing oligoesters obtained from step (iii) is precipitated. For this purpose, the mixture is preferably dissolved in dichloromethane. It can then be preferably precipitated in a non-solvent, for example methanol. After subsequent separation of the precipitated mixture containing oligoesters from the non-solvent and, optionally, drying, the mixture according to the invention containing oligoesters is obtained. Step (iv) can be used when the proportion of oligomers with a molecular weight of less than 1000 g / mol in the mixture is greater than 12%. The effect of the precipitation is that oligomers with a low molecular weight remain in solution. Thus, the proportion of oligomers with a molecular weight of less than 1000 g / mol in the mixture can be reduced.

[0030] Also optionally, the process according to the invention can optionally comprise, in addition to step (iv), a further step (v) in which the mixture containing oligoesters obtained from step (iii) or from step (iv) is reacted with a diacid diphenyl ester, preferably diphenyl isophthalate and / or diphenyl terephthalate. Process step (v) is particularly applicable when the mixture containing oligoesters obtained from step (iii) or step (iv) has an OH end group content of more than 0.5% by weight. By additional reaction with diacid diphenyl esters, at least some of the OH end groups can be converted into phenoxy end groups (i.e. Z in formula (1) is phenyl). In this way, the OH end group content of the mixture containing oligoesters can be reduced. The skilled person will also recognize alternative steps (v) for reducing the OH end group content. However, the described step (v) is particularly preferred, since the introduction of the described end groups leads to reactivity in the subsequent melt transesterification process to give polyester carbonates.

[0031] However, according to the invention, it is likewise possible, by suitable selection of parameters, and more particularly of a suitable catalyst in step (ii), even after step (iii), to obtain mixtures comprising oligoesters which directly meet the characteristics required according to the invention with regard to the OH end group content and the proportion of oligomers with a molecular weight of less than 1000 g / mol, so that in this case neither step (iv) nor step (v) is necessary.

[0032] For example, in step (i), the ratio of isophthalic acid and / or terephthalic acid to the diol of formula (3) preferably directly influences the resulting ratio of end groups in the mixture containing the oligoester. The ratio of isophthalic acid and / or terephthalic acid to the diol of formula (3) is preferably 1.00 to 1.15, more preferably 1.03 to 1.13, most preferably 1.04 to 1.12. It has been found that when the ratio is less than 1.00, a high proportion of oligomers with a molecular weight of less than 1000 g / mol is formed. As already described, these can be removed from the mixture by step (iv). However, this ratio is therefore preferably above 1.00. Conversely, an excessively high ratio leads to a very high OH end group termination. Again, it has already been described that this can be reduced by step (v). Nevertheless, this ratio is therefore preferably less than or equal to 1.15.

[0033] Preferably, both isophthalic acid and terephthalic acid are used in process step (i). When both diacids are used, it is further preferred that the ratio of isophthalic acid to terephthalic acid is 0.25-4.0:1, more preferably 0.4-2.5:1, most preferably 0.67-1.5:1. It is also preferred that the diol of formula (3) is resorcinol. It is also and preferably simultaneously preferred that the diaryl carbonate of formula (4) is diphenyl carbonate.

[0034] It is particularly preferred to use a ratio of isophthalic acid and / or terephthalic acid to diaryl carbonate of formula (4) of 1:2-2.5, more preferably 1.0:2.01-2.25, most preferably 1.0:2.05.

[0035] In process step (ii), the mixture from process step (i) is heated in the presence of at least one catalyst. Preferably, in this process step (ii), the individual components from process step (i) are melted. However, terephthalic acid in particular does not dissolve under the given conditions, at least at the beginning. However, this can be changed in the course of process step (ii). In process step (ii), carbon dioxide is usually released. This procedure allows a fast reaction with low thermal stress. Process step (ii) is preferably carried out under a protective gas atmosphere, preferably under nitrogen and / or argon. Step (ii) is preferably carried out in the absence of a solvent. The term "solvent" in this context is known to the skilled person. According to the present invention, the term "solvent" is preferably understood to mean a compound that does not initiate a chemical reaction in any of process steps (i), (ii) and / or (iii). This excludes compounds that are formed by reaction (e.g. phenols when the diaryl carbonate used is diphenyl carbonate). Of course, the presence of traces of solvents in the starting compounds cannot be excluded. This possibility is preferably covered by the present invention. However, according to the present invention, active steps of adding such solvents are preferably avoided.

[0036] Heating in process step (ii) is preferably carried out at temperatures between 180°C and 300°C, preferably between 190°C and 270°C, particularly preferably between 195°C and 250°C. Under these temperature conditions, the corresponding aryl alcohol of the diaryl carbonate, preferably the phenol, can be distilled off. Process step (ii) is preferably carried out under standard pressure. Here, stirring under standard pressure is preferred until the evolution of gases has substantially ceased. Alternatively, depending on the observed reactivity, the temperature can also be increased stepwise up to 200°C to 300°C, preferably 210°C to 260°C, particularly preferably 215°C to 240°C. The reactivity can be estimated from the evolution of gases in a manner known to the skilled person. Higher temperatures are in principle possible in this step, but at higher temperatures side reactions (discoloration, etc.) can occur. Higher temperatures are therefore less preferred.

[0037] It has been found that at least one catalyst used in process step (ii) can affect the oligomer distribution of the mixture according to the invention containing oligoesters. In process step (ii), it is (also) possible to use a catalyst containing alkali metal ions, preferably sodium ions. However, the alkali metal ions remain in the mixture according to the invention, which will then be condensed by melt transesterification. However, since alkali metal ions, especially sodium ions, can catalyze melt transesterification, the amount of sodium remaining in the mixture should be precisely known and, if necessary, determined. Therefore, it is advantageous not to use a catalyst containing alkali metal ions in process step (ii).

[0038] The at least one catalyst is more preferably an organic base, preferably an alkylamine, imidazole (derivatives), guanidine bases such as triazabicyclodecene, DMAP and corresponding derivatives, 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) and diazabicycloundecene (DBU), most preferably DMAP. These catalysts offer the particular advantage that they can be removed by the reduced pressure applied in the process step (iii) according to the invention. This means that the mixture containing the oligoester obtained has a low content of catalyst or even no catalyst at all. This offers the particular advantage that inorganic salts, which are always obtained, for example, by the route in which phosgene is used, are not present in the mixture of oligoesters and therefore also in the subsequent polyestercarbonates. It is known that such salts can have a negative effect on the stability of polyestercarbonates, since their ions can act catalytically in the case of the corresponding decomposition.

[0039] It is preferred to use a mixture of at least one organic base, such as an alkylamine, imidazole (derivatives), a guanidine base such as triazabicyclodecene, DMAP and corresponding derivatives, DBN or DBU together with a phosphonium catalyst of formula (VIII) (see further below).The catalyst used in process step (ii) is most preferably a mixture of 4-(dimethylamino)pyridine (DMAP) and tetrabutylphosphonium acetate.

[0040] At least one catalyst is preferably used in an amount of 1 ppm to 5000 ppm, preferably 5 ppm to 1000 ppm, more preferably 20 ppm to 500 ppm, based on the total mass of isophthalic acid and / or terephthalic acid, diol of formula (3), and diaryl carbonate of formula (4). When two or more catalysts are used in the reaction, these catalysts are preferably used in an amount of 1 ppm to 5000 ppm, preferably 5 ppm to 1000 ppm, more preferably 300 ppm to 700 ppm.

[0041] In process step (iii), a reduced pressure is applied to the mixture obtained from process step (ii), so that the corresponding aryl alcohol, preferably phenol, of the diaryl carbonate used is distilled off and the reaction equilibrium shifts towards the oligoester. The aryl alcohol is the chemical compound eliminated by the condensation reaction.

[0042] The term "condensation" is known to those skilled in the art. It is preferably understood to mean a reaction in which two molecules (of the same or different substances) combine to form one larger molecule, with the elimination of one molecule of a chemically simple substance. This compound eliminated during the condensation is removed in process step (iii) by reduced pressure. The process according to the invention is therefore preferably characterized in that during process step (iii) volatile components having a boiling point below the boiling point of the mixture of oligoesters formed in process step (ii) are removed, optionally using a stepwise reduction in pressure. When different volatile components are removed, a stepwise removal is preferably selected. A stepwise removal is likewise preferably selected in order to ensure that the volatile component(s) are removed as completely as possible. The volatile components are the chemical compound(s) eliminated during the condensation, preferably phenols.

[0043] To ensure continuous removal of chemical compounds that desorb in the condensation, the pressure can be reduced in stages, for example by reducing the pressure as soon as the overhead temperature drops.

[0044] The condensation product is preferably removed in process step (iii) at a temperature of 200° C. to 280° C., more preferably 210° C. to 270° C., particularly preferably 220° C. to 265° C. Furthermore, the reduced pressure during the removal is preferably 500 mbar to 0.01 mbar. It is particularly preferred that the removal is carried out stepwise by reducing the pressure. The degree of vacuum in the final stage is most preferably 10 mbar to 0.01 mbar.

[0045] In a first aspect of the present invention, (A) an ester group of formula (I) [ka] (In the formula, R 1 is independently in each occurrence a hydrogen atom, a halogen, or an alkyl group having 1 to 4 carbon atoms, preferably hydrogen; n is at least 4, preferably 4 to 30, more preferably 5 to 27, and most preferably 5 to 24; and "*" indicates the position at which the ester group is incorporated into the polyestercarbonate; (B) A carbonate group of formula (II) [ka] wherein Y, at each occurrence, is independently a structure of formula (III), (IV), (V), or (VI); [ka] During the ceremony, R6 and R7 are each independently hydrogen, C 1 ~C 18 Alkyl, C 1 ~C 18 alkoxy, halogen, or in each case optionally substituted aryl or aralkyl, preferably hydrogen; X is a single bond, -CO-, -O-, -S-, C 1 ~C 6 Alkylene, C 2 ~C 5 Alkylidene, C 6 ~C 10 Cycloalkylidene or C optionally fused with a further aromatic ring containing a heteroatom 6 ~C 12 Arylene, preferably a single bond, C 2 ~C 5 Alkylidene, C 6 ~C 10 cycloalkylidene, more preferably isopropylidene; [ka] In these formulas (IV) to (VI), R 3 In each case, C 1 ~C 4 alkyl, aralkyl or aryl, preferably methyl or phenyl, most preferably methyl; "*" indicates in each case the position at which formula (III), (IV), (V) or (VI) is attached to the carbonate group of formula (II); m is at least 5, preferably 8 to 300, more preferably 10 to 250, and most preferably 50 to 200, and each "*" indicates the position at which the carbonate group is incorporated into the polyester carbonate; In the polyester carbonate, At least a portion of the ester groups (A) are directly bonded to at least a portion of the carbonate groups (B) via formula (VII), [ka] wherein Y has the definition above for (B), (A) represents a bond to the ester group (A) and (B) represents a bond to the carbonate group (B); The polyester carbonate has a phenolic OH group content in the range of more than 0 ppm to 500 ppm or less, The polyester carbonate has a relative solution viscosity of at least 1.255 and at most 1.35. A polyester carbonate is provided, characterized in that

[0046] The presence of the structure of formula (VII) can be determined by NMR. This is indicated, for example, by the direct linkage of the bisphenol unit to the isophthalic and / or terephthalic acid unit. This linkage is an ester bond. The presence of this linkage can be determined by determining the chemical shift of the carbonyl carbon atom identified by the arrow in formula (VIIa). 13 It can be determined by C NMR spectroscopy. [ka]

[0047] In the experimental section, 13 To discover / calibrate the position of the carbons identified by the arrows in formula (VIIa) in the C NMR, the synthesis of a model compound formed from bisphenol A and isophthalic acid / terephthalic acid is illustrated as an example.

[0048] Polyestercarbonates produced by the interfacial process containing ester groups (A) and (B) do not have structural formula (VII) (see FIG. 1). In such reactions, an OH-terminated oligoester is reacted with a bisphenol (usually bisphenol A) or the corresponding oligocarbonate which gives the carbonate upon reaction with phosgene. This means that there is always a resorcinol unit bonded directly to a BPA unit via a carbonate group, for example.

[0049] It will be clear to the skilled person that the ester group (A) and the carbonate group (B) can each occur repeatedly in the polyester carbonate. It will also be clear that n and m, as well as the number of ester groups (A) and / or carbonate groups (B), must be selected so that the corresponding solution viscosity of the polyester carbonate is obtained. Here, it is preferred that the polyester carbonate according to the invention has a ratio of ester groups (A) of 5% to 90% by weight, more preferably 8% to 30% by weight, most preferably 9% to 25% by weight, based on the total weight of ester groups (A) and carbonate groups (B). It is also preferred that the polyester carbonate according to the invention consists of at least about 80% by weight, more preferably at least about 90% by weight, most preferably at least about 95% by weight of units of formulae (I) and (II).

[0050] The polyester carbonates according to the invention are preferably characterized by a relative solution viscosity of at least 1.26 and at most 1.34. As already mentioned above, this relative solution viscosity ensures good processability of the polyester carbonates, for example by injection molding. This relative solution viscosity likewise allows good mechanical properties to be displayed for the fields of use of interest, such as automotive exteriors. The polyester carbonates have high stability and are essentially stable to weathering.

[0051] According to the invention, the relative solution viscosity (ηrel; also called eta rel) is preferably determined with an Ubbelohde viscometer in dichloromethane at a concentration of 5 g / l at 25° C. The skilled person is familiar with the determination of the relative solution viscosity with an Ubbelohde viscometer. According to the invention, this is preferably carried out in accordance with DIN 51562-3; 1985-05. This then involves measuring the flow time of the polyestercarbonate to be analyzed through the Ubbelohde viscometer in order to determine the difference in viscosity between the polymer solution and its solvent. For this purpose, the Ubbelohde viscometer is first calibrated by analyzing the pure solvents dichloromethane, trichloroethylene and tetrachloroethylene (always carrying out at least three and at most nine measurements). This is followed by an appropriate calibration using the solvent dichloromethane. A polymer sample is then weighed and dissolved in dichloromethane, and the flow time is then determined three times for this solution. The average values ​​for the flow times are corrected by the Hagenbach correction and the relative solution viscosity is calculated.

[0052] It is also preferred that the polyester carbonates according to the invention have a phenolic OH group content in the range from more than 50 ppm to less than 400 ppm, more preferably more than 80 ppm to less than 350 ppm. This phenolic OH group content is preferably determined by infrared spectroscopy. As mentioned above with respect to the OH end groups of the mixtures according to the invention, 1It can also be determined by H NMR. Here, however, signals can overlap. The phenolic OH group content is therefore preferably determined by infrared spectroscopy. For this purpose, the polyester carbonate is preferably dissolved in dichloromethane (2 g / 50 ml) and the 3583 cm -1 The calibration of infrared instruments required for this purpose is known to those skilled in the art.

[0053] According to the present invention, R 1 is preferably hydrogen. Similarly, it is preferable that Y in formula (II) is a structure of formula (III).

[0054] Furthermore, R6 and R7 in formula (III) are each independently hydrogen or C 1 ~C 12 Alkyl, more preferably hydrogen or C 1 ~C 8 It is preferably alkyl, most preferably hydrogen or methyl.

[0055] It is very particularly preferred that Y is introduced into the carbonate group (B) via a diphenol selected from the group consisting of 4'-dihydroxydiphenyl, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 2,4-bis(4-hydroxyphenyl)-2-methylbutane, 1,1-bis(4-hydroxyphenyl)-p-diisopropylbenzene, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, dimethylbisphenol A, bis(3,5-dimethyl-4-hydroxyphenyl)methane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, bis(3,5-dimethyl-4-hydroxyphenyl)sulfone, 2,4-bis(3,5-dimethyl-4-hydroxyphenyl)-2-methylbutane, 1,1-bis(3,5-dimethyl-4-hydroxyphenyl)-p-diisopropylbenzene and 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, more preferably via bisphenol A.

[0056] The polyester carbonate according to the invention can be processed as it is to obtain any kind of molding. It can also be processed together with other thermoplastics and / or polymer additives to obtain thermoplastic molding compounds. The invention further provides molding compounds and moldings. The polymer additives are preferably selected from the group consisting of flame retardants, anti-drip agents, flame retardant synergists, smoke inhibitors, lubricants and release agents, nucleating agents, antistatic agents, conductive additives, stabilizers (e.g. hydrolysis, heat aging and UV stabilizers, and transesterification inhibitors), flow promoters, phase compatibilizers, dyes and pigments, impact modifiers, and fillers and reinforcing agents.

[0057] Thermoplastic molding compounds can be produced in known manner, for example by mixing polyester carbonates with further components and melt compounding and melt extruding them in conventional equipment, for example internal kneaders, extruders, twin-screw systems, preferably at temperatures between 200° C. and 320° C. In the context of the present application, this process is usually called compounding. The term "molding compound" is therefore understood to mean the product obtained when the components of the composition are melt compounded and melt extruded.

[0058] Molded articles formed from the polyester carbonates according to the invention or from thermoplastic molding compounds containing said polyester carbonates can be produced, for example, by injection molding, extrusion and blow molding processes.A further form of processing is the production of moldings by thermoforming from previously produced sheets or films.

[0059] In a further aspect of the present invention there is provided a process for the preparation of polyestercarbonates according to the invention, characterized in that a mixture according to the invention comprising an oligoester is reacted with a mixture of oligocarbonates by melt transesterification.

[0060] The process of melt transesterification is known per se to the person skilled in the art. Here, reference can be made, for example, to Schnell, "Chemistry and Physics of Polycarbonates", Polymer Reviews, Volume 9, Interscience Publishers, New York, London, Sydney 1964. In particular, this is a process that can be carried out without solvent and / or phosgene. For this purpose, it is necessary to melt the mixture comprising the oligoester and also the mixture of the oligocarbonate. Temperatures suitable for this purpose are usually 280°C to 400°C, preferably 300°C to 390°C, more preferably 305°C to 350°C, even more preferably 310°C to 340°C. However, according to the invention, it has been found that temperatures below 320°C, preferably above 280°C to 315°C, are advantageous for the incorporation of oligoester blocks into polyestercarbonates. This is particularly true when mixtures comprising oligoesters are used that have a high OH end group content within the range defined by the invention.

[0061] At the same time, a reduced pressure is applied to shift the reaction equilibrium towards the polyester carbonate side. The pressure used for this purpose is preferably 0.001 mbar to 50 mbar, more preferably 0.005 mbar to 40 mbar, even more preferably 0.02 mbar to 30 mbar, even more preferably 0.03 mbar to 5 mbar.

[0062] Here, the mixture of oligocarbonates preferably has a phenolic OH group content of 250 ppm to 2500 ppm, preferably 500 ppm to 2400 ppm, particularly preferably 1000 ppm to 2300 ppm. The determination of the phenolic OH group content has already been described above.

[0063] It is likewise preferable for the mixture of oligocarbonates to have a relative solution viscosity of 1.08 to 1.22, preferably 1.11 to 1.22, preferably 1.13 to 1.20. The determination of the relative solution viscosity has also already been described above.

[0064] The skilled person will be able to select the chemical nature of the oligocarbonates so as to obtain the carbonate groups (B) of the polyestercarbonates according to the invention. Bisphenol A-based oligocarbonates are particularly preferred.

[0065] The process according to the present invention is preferably carried out in the absence of catalyst.This has the advantage that catalyst does not need to be removed from the polyester carbonate obtained and does not remain therein.With catalyst, this may affect the stability of polyester carbonate.The process according to the present invention can also be carried out in the presence of catalyst, particularly preferably in the presence of basic catalyst.

[0066] Suitable catalysts include all inorganic or organic basic compounds, such as hydroxides, carbonates, halides, phenoxides, diphenoxides, fluorides, acetates, phosphates, hydrogen phosphates and borates of lithium, sodium, potassium, cesium, calcium, barium and magnesium, nitrogen bases and phosphites, such as tetramethylammonium hydroxide, tetramethylammonium acetate, tetramethylammonium fluoride, tetramethylammonium tetraphenylborate, tetraphenylphosphonium fluoride, tetraphenylphosphonium tetraphenylborate, dimethyldiphenylammonium hydroxide, tetraethylammonium hydroxide, cetyltrimethylammonium tetraphenylborate, cetyltrimethylammonium phenoxide, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBU), DBN) or guanidines, for example 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-phenyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7,7'-hexylidene-di-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7,7'-decylidene-di-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7,7'-dodecylidene-di-1,5,7-triazabicyclo[4.4.0]dec-5-ene, Lidenedi-1,5,7-triazabicyclo[4.4.0]dec-5-ene, or phosphazenes, such as the phosphazene base P1-t-oct = tert-octylimino tris(dimethylamino)phosphorane, the phosphazene base P1-t-butyl = tert-butyliminotris(dimethylamino)phosphorane, and BEMP = 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diaza-2-phosphorane.

[0067] Particularly suitable are phosphonium catalysts of formula (VIII): [ka] In the formula, Ra, Rb, Rc and Rd are the same or different C 1~C 10 Alkyl, C 6 ~C 14 Aryl, C 7 ~C 15 Aryl alkyl or C 5 ~C 6 Cycloalkyl, preferably methyl or C 6 ~C 14 aryl, particularly preferably methyl or phenyl; X - may be an anion such as hydroxide, sulfate, hydrogen sulfate, hydrogen carbonate, carbonate or a halide, preferably chloride, or an alkoxide or aroxide of formula -OR, where R is C 6 ~C 14 Aryl, C 7 ~C 15 Aryl alkyl or C 5 ~C 6 It may be cycloalkyl, preferably phenyl.

[0068] Particularly preferred catalysts are tetraphenylphosphonium chloride, tetraphenylphosphonium hydroxide and tetraphenylphosphonium phenoxide, the latter being very particularly preferred. Tetrabutylphosphonium acetate is likewise preferred.

[0069] These catalysts were used in a concentration of 10 -2 mol~10 -8 The amount of the alkali salt used as a promoter can be in the range of 1 ppb to 500 ppb, preferably 5 ppb to 300 ppb, particularly preferably 5 ppb to 200 ppb.

[0070] In a further aspect of the present invention there is provided a polyestercarbonate obtainable by the above process according to the invention in all the disclosed combinations and preferred forms. [Brief description of the drawings]

[0071] [Figure 1]FIG. 1 shows details from a 13C NMR spectrum of a commercial product containing isophthalic / terephthalic-resorcinol ester blocks and BPA prepared by an interfacial process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLES

[0072] Materials used: Terephthalic acid: synthetic, CAS100-21-0, Bernd Kraft, Duisburg Isophthalic acid: 99%, CAS121-91-5, Sigma-Aldrich Resorcinol: 99%, CAS108-46-3, ABCR Diphenyl Carbonate: Diphenyl Carbonate, 99.5%, CAS 102-09-0; Acros Organics, Geel, Belgium, abbreviated as DPC 4-Dimethylaminopyridine: 4-Dimethylaminopyridine; ≥98.0%; pure; CAS1122-58-3; Sigma-Aldrich, Munich, Germany, abbreviated as DMAP Tetrabutylphosphonium acetate: CAS-34430-94-9, prepared according to Angewandte Chemie, International Edition, Vol. 48, Issue: 40, 7398-7401; 2009 Sodium benzoate: ≥99%, CAS532-32-1, Sigma-Aldrich Oligocarbonate: The starting material used for the preparation of the polyester carbonate was a linear bisphenol A oligocarbonate containing phenyl end groups and phenolic OH end groups and having a relative solution viscosity of 1.17. This oligocarbonate does not contain any additives such as UV stabilizers, mold release agents or heat stabilizers. The oligocarbonate was prepared by the melt transesterification process as described in WO 02085967 and was immediately removed at the outlet from the first horizontal reactor. The oligocarbonate has a phenolic end group content of 0.16% by weight.

[0073] Analysis method: Solution viscosity: Determination of solution viscosity: The relative solution viscosity (ηrel; also called eta rel) was determined in dichloromethane at 25° C. and a concentration of 5 g / l using an Ubbelohde viscometer.

[0074] GPC: The molecular weight was determined by gel permeation chromatography using dichloromethane as eluent. The standard used was BPA polycarbonate. The signal from a refractive index detector was used. The corresponding method is defined by Currenta GmbH & Co. OHG under No. 2301-0257502-09D and can be obtained at any time from Currenta.

[0075] The oligomer content was also determined by GPC. This was done using the refractive index signal (RID). The oligomer range was defined as the range of molecular weight distribution below 1000 g / mol. The range below 1000 g / mol was evaluated as an area percentage by integration compared to the total area of ​​the distribution curve.

[0076] Determination of phenolic OH end group content: By infrared spectroscopy: Polyester carbonates dissolved in dichloromethane (2 g / 50 ml; 1 mm quartz cuvette) were analyzed on a Nicolet iS10 FT infrared spectrometer from Thermo Fisher Scientific. The phenolic OH end group content was determined at a wave number of 3583 cm. -1 The bands were determined by evaluating the bands at 1By H NMR spectroscopy: measurements were carried out in dichloromethane with tetramethylsiloxane as internal standard. The OH group content is reported in weight % relative to the oligomer. For evaluation, the OH group signals were integrated and expressed relative to the signal from the oligomer. Typically, the resonance of the OH group of the oligomer is between 5.3 ppm and 5.6 ppm. (However, the skilled artisan will recognize that the OH signal in NMR may move according to conditions such as the water content in the solvent).

[0077] The ratio of phenyl end groups to OH end groups is 1 The NMR spectra were determined by H NMR spectroscopy (Bruker, 700 MHz). Measurements were performed in dichloromethane with tetramethylsiloxane as an internal standard, where the area of ​​the peak at approximately 7.4 ppm (2 protons) was expressed relative to the area of ​​the peak between 6.6 ppm and 6.8 ppm (3 protons).

[0078] The bond between isophthalic acid and / or terephthalic acid units and bisphenol A (see chemical formula (VII)) 13 It was detected by C NMR spectroscopy.

[0079] The carbonyl carbon atom shows a shift at 164 ppm to 165 ppm, while the isophthalic and / or terephthalic acid resorcinol esters show a signal at about 163 ppm to 164 ppm.

[0080] The measurements were performed using a Bruker Avance III HD 600 MHz NMR spectrometer. 3 The analysis was performed using tetramethylsilane as a standard.

[0081] Preparation of model ester compounds from BPA and terephthalic acid / isophthalic acid. 21.9 mmol of BPA and a total of 21.9 mmol of diphenyl esters formed from terephthalic and isophthalic acids formed the initial charge in a multi-necked round bottom flask. 2.4 mg of tetrabutylphosphonium acetate was added, representing 0.02% of the total mass. The contents of the flask were freed of oxygen by evacuation and inerting with nitrogen four times. The mixture was heated to 200°C with constant stirring. Continuous formation of condensate occurred. The initially cloudy liquid mixture gradually became more transparent as the formation of phenol increased. An orange color was established, which increased in intensity as the temperature increased to 230°C. Approximately 80 minutes after the start of the reaction, the pressure was reduced to 10 mbar to 100 mbar in order to remove the phenol. A homogeneous orange-brownish product was removed.

[0082] 13 C NMR (600 MHz): 164.2 ppm to 164.5 ppm (m, 1C); IPS / TPS-BPA ester C atom (bond between isophthalic acid and / or terephthalic acid unit and resorcinol) [ka]

[0083] This material was prepared in order to clearly identify signals from the ester carbon atoms characteristic of esters formed from BPA and terephthalic or isophthalic acid. The corresponding signals were shown to be at 164.2 ppm to 164.5 ppm.

[0084] Preparation of Oligoesters for Comparative Examples Example 1 A flask equipped with a single-path separator was charged with 24.93 g (0.15 mol) of terephthalic acid, 24.93 g (0.15 mol) of isophthalic acid, 42.94 g (0.39 mol) of resorcinol, and further 130.46 g (0.609 mol) of diphenyl carbonate, 0.0447 g of DMAP (4-dimethylaminopyridine; 200 ppm relative to the starting material), and 9.9 μl of an aqueous solution of sodium benzoate (131.37 g / l) (corresponding to about 1 ppm of sodium). The mixture was deoxygenated by evacuating four times and filling with nitrogen. The mixture was melted and heated to 200° C. at standard pressure with stirring. The result was a suspension, since the terephthalic acid did not initially dissolve in the melt. The reaction mixture was stirred at that temperature for about 3 hours. This resulted in the evolution of carbon dioxide. The mixture was gradually heated to 240° C. The phenol was distilled off. The mixture was stirred at 240° C. for about 1 h. Finally, the mixture was stirred at 260° C. for another half hour. After the evolution of gas had ceased, the reaction mixture was cooled to 210° C. and the pressure was reduced. The pressure was reduced stepwise to 60 mbar within 45 min. The temperature was increased to 230° C. and the mixture was stirred at that temperature for half an hour. Then the temperature was increased to 245° C. The reaction mixture was stirred for a further 0.5 h and then the pressure was reduced to the technically feasible minimum (about 1 mbar). This resulted in a light brown melt. The analytical data are summarized in Table 1.

[0085] Example 2 The example was carried out basically in the same manner as in Example 1.

[0086] Deviating from Example 1, a flask equipped with a single-path separator was charged with 26.18 g (0.1575 mol) of terephthalic acid, 26.18 g (0.1575 mol) of isophthalic acid, 33.03 g (0.30 mol) of resorcinol, and further 141.69 g (0.6615 mol) of diphenyl carbonate, and 0.0441 g of DMAP (4-dimethylaminopyridine; 200 ppm with respect to the starting material) and 9.9 μl of an aqueous solution of sodium benzoate (131.37 g / l), corresponding to approximately 1 ppm of sodium.

[0087] Unlike Example 1, a greenish colored oligoester was obtained.

[0088] Example 3 The example was carried out basically in the same manner as in Example 1.

[0089] Deviating from Example 1, a flask equipped with a single-path separator was charged with 8.31 g (0.0500 mol) of terephthalic acid, 8.31 g (0.0500 mol) of isophthalic acid, 11.56 g (0.105 mol) of resorcinol, and further 43.91 g (0.205 mol) of diphenyl carbonate, and 0.0144 g of DMAP (4-dimethylaminopyridine; 200 ppm with respect to the starting material) and 3.2 μl of an aqueous solution of sodium benzoate (131.37 g / l), corresponding to approximately 1 ppm of sodium.

[0090] The mixture was melted at 160° C. and heated to 260° C. as quickly as allowed by gas evolution. When no more gas was evolved and the suspension turned into a solution, a holding phase of 0.5 h was applied. The depressurization phase was carried out as in Example 1.

[0091] Example 4 The example was carried out basically in the same manner as in Example 1.

[0092] Unlike Example 1, a flask equipped with a single-path separator was charged with 24.93 g (0.1500 mol) of terephthalic acid, 24.93 g (0.1500 mol) of isophthalic acid, 42.94 g (0.39 mol) of resorcinol, and 130.46 g (0.609 mol) of diphenyl carbonate, and 0.04465 g of DMAP (4-dimethylaminopyridine; 200 ppm relative to the feed).

[0093] The oligoesters prepared using these modified preparation parameters had similar characteristics to their sodium counterparts, except for the OH concentration.

[0094] Example 5 The product from Example 4 was dissolved in dichloromethane and then precipitated into methanol.

[0095] Example 6 The example was carried out basically in the same manner as in Example 2.

[0096] Unlike Example 2, a flask equipped with a single-path separator was charged with 25.35 g (0.1525 mol) of terephthalic acid, 25.35 g (0.1525 mol) of isophthalic acid, 33.03 g (0.30 mol) of resorcinol, and 131.73 g (0.609 mol) of diphenyl carbonate, and 0.0858 g of DMAP (4-dimethylaminopyridine; 400 ppm relative to the feed).

[0097] The oligoesters prepared using these modified preparation parameters had similar characteristics to their sodium counterparts.

[0098] Preparation of Oligoesters for the Examples of the Invention Example 7 The oligoester from Example 6 was dissolved in dichloromethane and then precipitated into methanol.

[0099] Example 8 The example was carried out basically in the same manner as in Example 1.

[0100] Unlike Example 1, a flask equipped with a single-path separator was charged with 20.77 g (0.125 mol) of terephthalic acid, 20.77 g (0.125 mol) of isophthalic acid, 28.90 g (0.2625 mol) of resorcinol, and 109.79 g (0.5125 mol) of diphenyl carbonate, and 0.036 g of DMAP (4-dimethylaminopyridine; 200 ppm relative to the feed), and 0.054 g of tetrabutylphosphonium acetate (300 ppm).

[0101] The experimental procedure was the same as in Example 1. Unlike Examples 2-7, the product had a melt viscosity that increased significantly upon removal.

[0102] Example 9 The example was carried out basically in the same manner as in Example 1.

[0103] Unlike Example 1, a flask equipped with a single-path separator was charged with 20.77 g (0.125 mol) of terephthalic acid, 20.77 g (0.125 mol) of isophthalic acid, 30.28 g (0.275 mol) of resorcinol, and 109.79 g (0.5125 mol) of diphenyl carbonate, and 0.036 g of DMAP (4-dimethylaminopyridine; 200 ppm relative to the feed), and 0.054 g of tetrabutylphosphonium acetate (300 ppm).

[0104] The experimental procedure was the same as in Example 1.

[0105] [Table 1]

[0106] Examples of polyestercarbonate synthesis from oligocarbonate and oligoester blocks from Examples 1 to 9 Example 10 (Comparative Example) A flask equipped with a single-path separator was charged with 32.0 g (80% by weight) of oligocarbonate and 8.0 g (20% by weight) of the oligocarbonate from Example 1. The mixture was deoxygenated by evacuating and filling with nitrogen four times. The mixture was melted at 160° C. under standard pressure. The temperature was then increased to 320° C. The pressure was reduced to the technically possible minimum (about 1.5 mbar). The temperature was increased stepwise to about 335° C. within 30 minutes; phenol was continuously removed. A clear melt was obtained. The analytical data are shown in Table 2.

[0107] Example 11 (Comparative Example) The experiment was carried out as described in Example 10. The difference was that 36.0 g of the oligocarbonate from Example 1 (90% by weight) and 4.0 g of the oligoester (10% by weight) were used.

[0108] Example 12 The experiment was carried out as described in Example 10. The difference was that the oligocarbonate from Example 2 was used.

[0109] Example 13 The experiment was carried out as described in Example 10. The difference was that 36.0 g of the oligocarbonate from Example 2 (90% by weight) and 4.0 g of the oligoester (10% by weight) were used.

[0110] Example 14 The experiment was carried out as described in Example 10. The difference was that the oligocarbonate from Example 3 was used.

[0111] Example 15 The experiment was carried out as described in Example 10. The difference was that 36.0 g of the oligocarbonate from Example 3 (90% by weight) and 4.0 g of the oligoester (10% by weight) were used.

[0112] Example 16 The experiment was carried out as described in Example 10. The difference was that 36.0 g of the oligocarbonate from Example 4 (90% by weight) and 4.0 g of the oligoester (10% by weight) were used.

[0113] Example 17 The experiment was carried out as described in Example 10. The difference was that the oligocarbonate from Example 4 was used.

[0114] Example 18 The experiment was carried out as described in Example 10. The difference was that 36.0 g of the oligocarbonate from Example 5 (90% by weight) and 4.0 g of the oligoester (10% by weight) were used.

[0115] Example 19 The experiment was carried out as described in Example 10. The difference was that the oligocarbonate from Example 5 was used.

[0116] Example 20 The experiment was carried out as described in Example 10. The difference was that 36.0 g of the oligocarbonate (90 wt%) from Example 6 and 4.0 g of the oligoester (10 wt%) were used. The increase in viscosity was small compared to the previous examples.

[0117] Example 21 The experiment was carried out as described in Example 10. The difference was that the oligocarbonate from Example 5 was used. The increase in viscosity was small compared to the previous examples.

[0118] Example 22 The experiment was carried out as described in Example 10. The difference was that 36.0 g of the oligocarbonate from Example 7 (90% by weight) and 4.0 g of the oligoester (10% by weight) were used.

[0119] Example 23 The experiment was carried out as described in Example 10. The difference was that the oligocarbonate from Example 7 was used.

[0120] Example 24 The experiment was carried out as described in Example 10. The difference was that 36.0 g of the oligocarbonate from Example 8 (90% by weight) and 4.0 g of the oligoester (10% by weight) were used.

[0121] Example 25 The experiment was carried out as described in Example 10. The difference was that the oligocarbonate from Example 8 was used.

[0122] Example 26 The experiment was carried out as described in Example 10. The difference was that 36.0 g of the oligocarbonate from Example 9 (90% by weight) and 4.0 g of the oligoester (10% by weight) were used.

[0123] Example 27 The experiment was carried out as described in Example 10. The difference was that the oligocarbonate from Example 9 was used.

[0124] [Table 2]

[0125] Experiments using Na catalyst In Example 1, a mostly OH-terminated oligoester is obtained (0.6% by weight OH). GPC of the oligoester shows only low levels of oligomers in the range below 1000 g / mol. This oligoester was used in Examples 1 and 2. Each final product shows a relatively high phenolic OH value, more than 500 ppm in Example 1. This therefore indicates that the ester block is not very suitable, since in no case is it possible to obtain a product below 500 ppm. Also, in Example 2, although it has an OH value below 500 ppm, the viscosity and therefore the molecular weight are very high. Therefore, it is very likely that the 500 ppm limit will be exceeded in the case of a correspondingly lower molecular weight.

[0126] In Example 2, an oligoester with a low OH content was prepared (0.2 wt%). This block is mostly phenyl-terminated. However, this block contains a well-defined amount of oligomers in the range of less than 1000 g / mol. As in Example 13, which used the oligoester block from Example 2, the increase in molecular weight is small compared to the other examples. Thus, in the case of the phenyl-terminated block with a relatively high oligomer content, a lower activity was found. Surprisingly, the desired molecular weight could not be achieved despite the use of a catalyst.

[0127] In Example 3, oligoesters with relatively high OH content (0.85 wt%) were prepared. Moreover, this product has a relatively high oligomer content in the range of less than 1000 g / mol. Example 15 shows that the corresponding polyester carbonate has a phenolic OH value of more than 500 ppm. Therefore, it is not possible to produce a full range of polyester carbonates with different ester contents.

[0128] Example 4 shows a mostly OH-terminated (0.80 wt.% OH) oligoester. Examples 16 and 17 have relatively high molecular weights (no need to use a catalyst) and therefore show that the OH-terminated blocks are highly reactive. However, the corresponding end products have high contents of phenolic OH end groups (>500 ppm) both in the case of 10% and 20% ester block content.

[0129] In example 5, the ester block from example 4 is precipitated. The content of phenolic OH end groups thus drops from 0.8% to 0.7% by weight. However, even with this block it is not possible to produce a product with an acceptable OH content (see examples 18 and 19).

[0130] In Example 6, oligoester blocks with acceptable OH content are used. However, the oligomer content in the range below 1000 g / mol is relatively high. As in Example 13, the reactivity is low here (Examples 20 and 21), and the molecular weight target range cannot be achieved.

[0131] In the present invention, in Examples 22 and 23, starting from oligoester blocks (from Example 7), polyestercarbonates with a low proportion of phenolic OH groups are prepared.It is therefore found that when using oligoesters with moderate OH content, it is possible to prepare polyestercarbonates according to the purpose.Despite the relatively low OH content of oligoester blocks, it is surprisingly possible to achieve relatively high molecular weights in polyestercarbonates.

[0132] Surprisingly, even in the case of very low OH contents (oligoester blocks from Example 8), it was possible to achieve high molecular weights in polyester carbonates (Examples 24 and 25). Furthermore, the resulting materials have low OH contents.

[0133] Inventive examples 26 and 27 likewise have a low OH content, where oligoester blocks with 0.2% by weight of phenolic OH groups were used.

Claims

1. A mixture comprising the oligoester of formula (1), 【Chemical 1】 Wherein, Each R １ Is independently a hydrogen atom, a halogen or an alkyl group having 1 to 4 carbon atoms, Each q is independently 0 or 1, When q = 1: Each Z is independently -H or an aromatic group of formula (2a), 【Chemical 2】 Wherein, R ２ ’ is hydrogen or -COOCH ３ And “*” indicates the position where the formula (2a) is bonded to the oxygen atom in the formula (1), When q = 0: Each Z is independently an aromatic group of formula (2), 【Chemical 3】 Wherein, R ２ Is hydrogen or -COOCH ３ And “*” indicates the position where the formula (2) is bonded to the oxygen atom in the formula (1), p indicates the number of repeating units, In the mixture, Not more than 0.5% by weight of the Z groups with respect to the mixture is hydrogen, and the percentage of oligomers having a molecular weight of less than 1000 g / mol in the mixture is less than 12%, where the percentage of oligomers is determined by the ratio of the area under the molecular weight distribution curve of the mixture to the refractive index signal (from gel permeation chromatography) in the range of less than 1000 g / mol to the total area under the molecular weight distribution curve, where the gel permeation chromatography is performed in dichloromethane using a bisphenol A polycarbonate standard, A mixture, characterized by the above.

2. R in formula (1) １ Is hydrogen, Not more than 0.4% by weight of the Z groups with respect to the mixture is hydrogen, the percentage of oligomers having a molecular weight of less than 1000 g / mol is less than 10%, the mixture according to claim 1, characterized in that.

3. (A) an ester group of formula (I) 【Chemical formula 4】 (wherein R １ is, in each case independently, a hydrogen atom, a halogen, or an alkyl group having 1 to 4 carbon atoms, n is at least 4, and "*" indicates the position where the ester group is incorporated into the polyester carbonate), (B) a carbonate group of formula (II) 【Chemical formula 5】 (wherein Y is, in each case independently, a structure of formula (III), (IV), (V) or (VI), 【Chemical formula 6】 in the formula, R6 and R7 are each independently hydrogen, C １ ~ C １８ alkyl, C １ ~ C １８ alkoxy, halogen, or in each case aryl, aralkyl, substituted aryl or substituted aralkyl, X is a single bond, -CO-, -O-, -S-, C １ ~ C ６ alkylene, C ２ ~ C ５ alkylidene, C ６ ~ C １０ cycloalkylidene, C ６ ~ C １２ arylene or C condensed with a further aromatic ring containing a heteroatom ６ ~ C １２ arylene, 【Chemical formula 7】 in these formulas (IV) to (VI), R ３ is, in each case, C １ ~ C ４Alkyl, aralkyl or aryl, preferably methyl or phenyl, most preferably methyl, "*" indicates the position at which the formula (III), (IV), (V) or (VI) is attached to the carbonate group of the formula (II) in each case, m is at least 5, and "*" indicates the position at which the carbonate group is incorporated into the polyester carbonate in each case), in a polyester carbonate comprising at least a part of the ester group (A) is directly bonded to at least a part of the carbonate group (B) via the formula (VII), [Chemical Formula 8] In the formula, Y has the above definition with respect to (B), (A) represents the bond to the ester group (A), and (B) represents the bond to the carbonate group (B), the polyester carbonate has a phenolic OH group content in the range of more than 0 ppm to 500 ppm or less, the polyester carbonate has a relative solution viscosity of at least 1.255 to at most 1.35, A polyester carbonate, characterized in that.

4. The polyester carbonate according to claim 3, wherein Y in the formula (II) has the structure of the formula (III).

5. The polyester carbonate according to claim 3 or 4, characterized in that the polyester carbonate has a phenolic OH group content in the range of more than 50 ppm to 400 ppm or less.

6. A molding compound comprising the polyester carbonate according to claim 3 or 4.

7. A molded article comprising the polyester carbonate according to claim 3 or 4.

8. A method for preparing a polyester carbonate according to any one of claims 4 to 10, characterized in that a mixture containing the oligoester according to claim 3 or 4 is reacted with a mixture of oligocarbonate by melt transesterification.

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