Polyester carbonate blends and their preparation by means of polyester carbonate prepolymers

Abstract

The invention relates to a method for producing a polyestercarbonate prepolymer, to a polyestercarbonate prepolymer, to a method for producing a polyestercarbonate blend by using a polyestercarbonate prepolymer, to a polyestercarbonate blend, and to the use of a polyestercarbonate prepolymer.

Description

[0001] The present invention relates to a method for preparing a polyester carbonate prepolymer, a polyester carbonate prepolymer, a method for preparing a polyester carbonate blend by using the polyester carbonate prepolymer, a polyester carbonate blend and use of the polyester carbonate prepolymer.

[0002] Polyester carbonates containing ester blocks formed by isophthalic acid and / or terephthalic acid and resorcinol have good weathering stability. These materials are particularly interesting because they do not require any coating to protect them from harmful weathering effects, especially UV damage. The ester structure formed by resorcinol and isophthalic acid and / or terephthalic acid can enter the so-called light-Fries rearrangement when exposed to UV light. In particular, hydroxybenzophenone structures incorporated into the polymer chain are formed here. Hydroxybenzophenone is known to have UV absorption properties. This explains the good weathering stability. For example, this theme is described in US20030050400 A1. In contrast, the alternative use of UV absorbers is much less effective because most of the UV absorbers accumulate in the body of the molded article. The concentration of UV absorbers on the surface of the molded article that must be protected, especially from UV damage, is relatively low. If a person skilled in the art wants to use a higher concentration of UV absorbers, they will face more disadvantages. For example, low molecular weight compounds, especially at higher concentrations, reduce mechanical properties. This is undesirable. In order to fix higher concentrations of UV absorbers on the surface, UV-sensitive materials such as polycarbonate are often protected with coatings with high concentrations of UV absorbers. However, painting is an additional step that incurs costs and is not always the preferred solution for sustainability reasons. Especially in the automotive application sector, it is advantageous if the material itself is weather-stable and laborious painting can be dispensed with.

[0003] The polyester carbonates are prepared in the prior art by the phase interface method. In this method, aromatic diols and OH-terminated ester blocks are condensed by phosgene. OH-terminated ester blocks can also be prepared in solution by phosgene condensation starting from aromatic diacids and aromatic diols. Such a method for preparing oligoesters and corresponding polyester carbonates is described in WO0026275A1. The document describes polyester carbonates as preferred polymers, which are formed from bisphenol A and contain ester blocks from resorcinol and terephthalic acid / isophthalic acid. Here, ester blocks are prepared starting from the acid chlorides of aromatic diacids and resorcinol using an aqueous NaOH solution in a dichloromethane / water mixture. The polyester solution containing the hydroxy-terminated ester blocks is transferred to a phosgenation reactor. Preferably, an alkaline bisphenol A solution is introduced and the reactants are reacted with phosgene.

[0004] According to DE60212172T2, the polyester carbonate is obtained by solid phase polymerization. The method is relatively complex, since it is always necessary to carry out a step of at least partially crystallizing the polycarbonate used. In addition, the document shows that, in particular, the use of an activated carbonate source (e.g., polycarbonate terminated with methyl salicylate) can achieve a sufficient molar mass of the polyester carbonate, and that the randomization of the groups can be at least partially suppressed. The document uses only OH-terminated oligoester blocks (i.e., the end groups of the oligoesters are usually resorcinol). This results in the same connection between the oligoester and the polycarbonate as described in the above-mentioned phase interface method (see Figure 2 ). This document clearly states that melt processes are not suitable for preparing such polyester carbonates, since the result is a random copolymer (i.e. the polyester blocks are degraded and randomly distributed in the polymer). From this alone it can already be seen that the reaction conditions for solid phase polymerization are not suitable for melt processes.

[0005] Processes based on the known melt transesterification process for polycarbonates are known and have the advantage that difficult-to-handle raw materials, such as phosgene, can be dispensed with. They also have the great advantage that no solvent is required. The preparation of polyester carbonates by the melt transesterification process is therefore industrially advantageous. However, this process also has challenges. For example, highly reactive acid chlorides can hardly be replaced by other raw materials. Transesterification processes generally have long residence times in the corresponding reactors. Due to the high temperatures, by-products are often formed which have an adverse effect on the product quality. Since the melt transesterification process generally does not require complex post-processing steps, impurities, such as residual catalyst, may remain in the product. These impurities reduce the product quality.

[0006] In addition, compared with the corresponding products from the phase interface method, the polycarbonate prepared by the melt transesterification method has a significantly higher hydroxyl-terminated end group content (phenolic OH group content). These phenolic OH groups may be damaged by oxidation processes, thereby reducing the product quality. This will especially affect the optical properties. However, it is very important to obtain good optical properties, especially when the product should have high inherent weathering stability. Therefore, it is advantageous that the phenolic OH end group content in the resulting polymer is low. However, there is no teaching about the polyester carbonate in the prior art, because the prior art only relates to the preparation of polyester carbonate by phase interface reaction.

[0007] Since the reactivity of the reactants is lower—compared to the starting materials in the phase interface process—for the reasons mentioned above, it is also not known how to prepare the above-mentioned polyester carbonates having a high viscosity or molecular weight.

[0008] It is known to prepare oligoester blocks from aromatic diacids (e.g. isophthalic acid and / or terephthalic acid) and aromatic diols (e.g. resorcinol). This is described, for example, in the as yet unpublished application EP21179513.3. Here, aromatic diacids and aromatic diols are reacted by means of DPC. With this process, oligoesters having various end groups (e.g. OH end groups or phenyl ester end groups or phenyl carbonate end groups) can be prepared.

[0009] However, it was surprisingly found that in the case of the reaction of such oligoesters with aromatic polycarbonate prepolymers, the content of ester structures formed from the corresponding isophthalic acid and / or terephthalic acid and the corresponding aromatic diols (especially resorcinol) present in the polyester carbonate is not sufficient to provide good intrinsic weathering stability. When the concentration of such structural elements is low, significantly fewer Fries products (especially hydroxybenzophenone structures) result. As a result, the intrinsic stability to UV rays is significantly lower. This finding is surprising because there is no suggestion in the prior art that the above structural elements are lost during the transesterification process.

[0010] WO2005021616 A1 describes the preparation of hydroxyl-terminated oligoester blocks in the molten state. The question here is how to make the OH end group content of the oligoesters comparable to that of the oligoesters obtained in the solvent process. The influence of different catalysts and operating modes (e.g. different temperatures and vacuum) is also tested for this purpose. In addition, the oligoesters are subsequently condensed to polyester carbonates by the phase interface method. Therefore, this document does not provide any teaching on how to retain the ester structure formed by isophthalic acid and / or terephthalic acid and resorcinol when preparing polyester carbonates by melt transesterification.

[0011] WO2006057810 A1 describes oligoesters prepared by the melt transesterification process, which are characterized in that they have a high proportion of carboxyl end groups. These carboxyl end groups are then utilized to incorporate the oligoesters into coating systems. Therefore, there is no description of the use of oligoesters in the melt transesterification process here either.

[0012] US20030050400 A1 describes the preparation of oligomers from aromatic diacids and resorcinol. The problem solved in US20030050400 A1 is to provide OH-terminated units which can then be converted into polyester carbonates by the interfacial process. Similar to WO2005021616 A1, the report here only deals with the interfacial process, so that no conclusions can be drawn that the desired ester structure is obtained in the melt process.

[0013] Starting from this prior art, the problem to be solved by the present invention is to overcome at least one disadvantage of the prior art. In particular, the problem to be solved by the present invention is to provide a polyester carbonate blend, which comprises an ester block based on isophthalic acid and / or terephthalic acid and an aromatic diol, preferably resorcinol, which ester block can be obtained by a melt transesterification process. The corresponding polyester carbonate blend here should contain an ester structure formed by aromatic acids and aromatic diols (not bisphenols) in as high a concentration as possible. Therefore, one aspect of the present invention is that the resulting polyester carbonate blend has good inherent weathering stability. This should especially be produced by complete ester groups formed by isophthalic acid and / or terephthalic acid and aromatic diols, especially resorcinol or derivative compounds. These complete groups can form hydroxybenzophenone structures, thereby giving the polyester carbonate blend UV absorption properties. This can improve the inherent weathering stability. The polyester carbonate blend should preferably have good processability at the same time. Most preferably, the blend should have a phenolic OH end group content as low as possible. Thus, the polyester carbonate blends should preferably be weather-stable and / or substantially resistant to yellowing and / or have substantially no tendency to polymer degradation, for example due to oxidative degradation. It is also preferred that no raw materials that are challenging to handle, such as phosgene, are used in the preparation of the polyester carbonate blends. Furthermore, a process for preparing the polyester carbonate blends should be provided that is as simple as possible, i.e., for example comprises as few and / or inexpensive and / or energy-intensive steps as possible.

[0014] The present invention solves at least one of the above problems, preferably all of them. Surprisingly, it has been found that when oligoesters containing ester bonds between isophthalic acid and / or terephthalic acid and resorcinol or compounds derived from resorcinol are mixed with oligoesters and / or polycarbonates or heat-treated together with polycarbonates according to the process of the invention, a high proportion of ester structures formed from aromatic diols (not bisphenols) and isophthalic acid and / or terephthalic acid can be obtained in the resulting polyester carbonate blend. When a large amount of oligoesters is reacted with a small amount of oligomeric and / or polycarbonate in a first process step and the resulting polyester carbonate prepolymer is reacted with a large amount of polycarbonate in a second process step, a polyester carbonate blend with a high proportion of ester structures formed from aromatic diols and aromatic acids can be obtained. The process of the invention leads to the obtaining of polyester carbonate blends in which the isophthalic acid and / or terephthalic acid groups are directly bonded to aromatic diols (e.g. resorcinol) in a high proportion by using specific polyester carbonate prepolymers. In addition, ester bonds formed from aromatic bisphenols (such as bisphenol A) and aromatic diacids are also included.

[0015] Without wishing to be bound by theory, the first process step of converting a large excess of oligoesters relative to oligoesters and / or polycarbonates appears to produce polyestercarbonate prepolymers, wherein the small amount of carbonate units combined with the oligoesters has good compatibility with the polycarbonate used in the second process step. This allows both polyestercarbonate prepolymers and polycarbonates to be converted into a homogeneous mixture in the second process step. This homogeneous mixture has good optical and mechanical properties. In addition, under these conditions, most of the esters of isophthalic acid esters and / or terephthalic acid with aromatic diols different from bisphenol A are still retained, so that the resulting blend also has inherent weathering stability.

[0016] In addition, polyester carbonate blends can be prepared using solvent-free methods. In particular, the use of difficult-to-handle substances, such as phosgene, can also be omitted. The method according to the invention also comprises only a few steps (in particular no complex crystallization steps, such as the crystallization steps of polycarbonates). In addition, these steps also do not require the presence of solvents (such as crystallization). This makes it possible to obtain polyester carbonate blends by a simple and environmentally and / or economically favorable method. In particular, the method according to the invention can also be scaled up. This preferably means that the method according to the invention can also be carried out on an industrial scale. This shows in particular that the method according to the invention can also be scaled up in a controllable manner, wherein the scale is therefore also predictable.

[0017] In addition, according to the process of the invention, prepolymers and / or blends can be provided without using activated carbonate sources (e.g. oligocarbonates or polycarbonates with 2-methoxycarbonylphenoxy end groups; see also DE60212172T2). Such activated carbonate sources are usually more expensive than conventional "unactivated" groups (e.g. oligocarbonates or polycarbonates with phenoxy end groups) and require special preparation in an additional step.

[0018] Therefore, according to the present invention, on the one hand, there is provided a method for preparing a polyester carbonate prepolymer, which comprises the following steps:

[0019] (a) providing an oligoester comprising a structure of formula (I)

[0020]

[0021] wherein R1 is each independently a hydrogen atom, a halogen or an alkyl group having 1 to 4 carbon atoms, and n is at least 4,

[0022] (b) providing oligocarbonates and / or polycarbonates, and

[0023] (c) reacting 65 to 95% by weight of the oligoester from step (a) with 35 to 5% by weight of the oligocarbonate and / or polycarbonate from step (b) by condensation reaction in the molten state to obtain a polyester carbonate prepolymer, wherein the % by weight are based on the total weight of the oligoester from step (a) and the oligocarbonate and / or polycarbonate from step (b).

[0024] The preparation of oligoesters from process step (a) is known in the prior art. For example, WO 2005 / 021616 A1 discloses a corresponding method, in particular for the preparation of OH-terminated oligoesters (see, for example, Example 1 of WO 2005 / 021616 A1). A method for preparing oligoesters is also described in the unpublished application EP 21179513.3.

[0025] Preferably, the oligoesters in step (a) are prepared without solvents. This means that no further purification steps are necessary to convert the oligoesters in step (c) according to the invention.

[0026] More preferably, the oligoester in step (a) is prepared by the following method:

[0027] [I] mixing at least isophthalic acid and / or terephthalic acid with a diol of formula (3) and at least one diaryl carbonate of formula (4), wherein

[0028]

[0029] wherein R1 is a hydrogen atom, a halogen or an alkyl group having 1 to 4 carbon atoms, preferably hydrogen, and wherein

[0030]

[0031] wherein R2 is each independently hydrogen or -COOCH3, preferably hydrogen,

[0032] [II] heating the mixture in step [I] in the presence of at least one catalyst, and

[0033] [III] Applying vacuum to the mixture of step [II] to obtain oligoesters.

[0034] If necessary and / or desired, work-up of the oligoesters can be carried out by methods known to those skilled in the art, for example by precipitation. However, preference is given to using no solvents during the work-up.

[0035] It will be clear to those skilled in the art that, for example, in Formula (I), Formula (3), Formula (300), Formula (Ia) and / or Formula (7), R 1The position of should be chosen so that the light-Fries rearrangement is possible. For example, it is not allowed that all adjacent positions are occupied by R 1 However, the possible substitution patterns will be clear to the skilled person based on his knowledge in the field.

[0036] According to the invention, reference is occasionally made to "aromatic diols". This expression is particularly used to distinguish it from "bisphenols" (it is also often pointed out that aromatic diols do not mean bisphenols). It is known to the person skilled in the art that bisphenols in a broad sense are also aromatic diols. However, in the context of the present invention, a corresponding distinction can be made based on the knowledge in the field (especially as to which structures have intrinsic UV activity and which do not). Aromatic diols are preferably understood to mean structures of formula (3). More preferably, aromatic diols are understood to mean resorcinol or compounds derived from resorcinol. "Bisphenol" in the present invention is preferably a compound of formula (III) (see "Y" in formula (II), wherein an OH group is present on the "*" in formula (III) (the structure of formula (III) is therefore a bisphenol structure formed by the reaction of OH groups; the person skilled in the art understands this relationship). A particularly preferred bisphenol is bisphenol A.

[0037] Likewise, the process may optionally have a further step in which the oligoester is reacted with a diphenyl diacid ester, preferably diphenyl isophthalate and / or diphenyl terephthalate. If desired, the OH end group content can be reduced by such a reaction.

[0038] The oligoester from method step (a) can be OH end-blocking, phenyl ester end-blocking, acid end-blocking or phenyl carbonate end-blocking, or comprise the mixture of above-mentioned end groups. The oligoester is preferably OH end-blocking, phenyl ester end-blocking or phenyl carbonate end-blocking, or there is any mixture of above-mentioned end groups. Those skilled in the art can adapt the method according to the present invention to comprised (one or more) end groups. For example, the end groups can be affected by the composition / ratio of monomers used, temperature of reaction, catalyst used and application of vacuum and the intensity of vacuum. Therefore, the viscosity of the oligoester and the resulting glass transition temperature can be affected equally.

[0039] It is particularly preferred that the oligoesters in step (a) of the process according to the invention at least partially do not have any OH end groups. This means that the resulting polyester carbonate prepolymers or the resulting polyester carbonate blends preferably contain essentially no, more preferably no, bonds of, for example, resorcinol to, for example, BPA via carbonate bridges. It is particularly preferred that the polyester carbonate prepolymers according to the invention and / or the polyester carbonate blends according to the invention (both described below) contain essentially no, more preferably no, structures of formula (300):

[0040]

[0041] wherein, in the structure of formula (300), R1 is each independently a hydrogen atom, a halogen or an alkyl group having 1 to 4 carbon atoms, preferably having the definition given for R1 in formula (Ia), Y is each independently a structure of formula (III), (IV), (V) or (VI), preferably having the definition given for formula (II), and "*" in each case indicates the position at which the structure of formula (300) is / will be incorporated into the polymer chain of the polyester carbonate.

[0042] The expression "substantially free of structures of formula (III)" will be understood by a person skilled in the art. Obviously, trace amounts of such groups may be present due to contamination. However, according to the present invention, they are preferably avoided.

[0043] In particular, it is preferred that the oligoesters in step (a) of the process according to the invention at least partially do not have any OH end groups, and the polyester carbonate prepolymers according to the invention are particularly preferably obtained by this process.

[0044] For example, in step (I), the end group ratio in the resulting oligoester can be influenced preferably by the molar ratio of isophthalic acid and / or terephthalic acid to the diol of formula (3). The molar ratio of isophthalic acid and / or terephthalic acid to the diol of formula (3) is preferably 0.50 to 1.20, more preferably 0.70 to 1.15, most preferably 0.75 to 1.12.

[0045] According to the invention, the diol of formula (3) is preferably also relatively frequently referred to as "resorcinol or a compound derived from resorcinol". This preferably means that, when the substituent R1 is present, a compound derived from resorcinol is present which has the substituent R1 defined as indicated.

[0046] Preferably, both isophthalic acid and terephthalic acid are used in process step (I). When both diacids are used, it is also preferred that the molar 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 also preferred that the diaryl carbonate of formula (4) is diphenyl carbonate.

[0047] It is particularly preferred to use a molar ratio of isophthalic acid and / or terephthalic acid to the diaryl carbonate of formula (4) of 1:2-2.5, more preferably 1.0:2.01-2.25, and most preferably 1.0:2.05.

[0048] 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, under given conditions, in particular terephthalic acid is at least not dissolved at the beginning. However, this situation can be changed during process step (II). In process step (II), carbon dioxide is usually released. This procedure allows a rapid reaction with a low temperature burden. 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" is known to those skilled in the art in this context. According to the present invention, the term "solvent" is preferably understood to mean a compound that does not participate in the chemical reaction in any of process steps (I), (II) and / or (III). This does not include those compounds formed by the reaction (for example, phenol when the diaryl carbonate used is diphenyl carbonate). Of course, it is impossible to exclude the inclusion of traces of solvent in the starting compound. According to the present invention, this situation should preferably be included. However, according to the present invention, active steps for adding such solvents are preferably avoided.

[0049] The heating in process step (II) is preferably carried out to a temperature of 180° C. to 320° C., preferably 190° C. to 310° C., particularly preferably 230° C. to 300° C. Under these temperature conditions, the corresponding aromatic alcohol of the diaryl carbonate, preferably phenol, may have been distilled off. Process step (II) is preferably carried out at standard pressure. It is preferred to stir at standard pressure until the gas release has essentially ceased. Alternatively, the temperature can also be increased stepwise to 200° C.-320° C., preferably 210-310° C., particularly preferably 215-300° C., depending on the observed reactivity. The reactivity can be estimated from the gas release in a manner known to those skilled in the art. Although higher temperatures can also be used in principle in this step, side reactions (such as discoloration) may occur at higher temperatures. Therefore, higher temperatures are less preferred.

[0050] More preferably, the at least one catalyst is an organic base or a Lewis acidic transition metal compound. The organic base is preferably an alkylamine, an imidazole (derivative), a guanidine base, 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 have the particular advantage that they can be separated by the vacuum applied in step (III) of the method according to the invention. This means that the resulting mixture containing oligoesters contains only a low content of catalyst, or even no catalyst at all. This has the particular advantage that no inorganic salts (which are always obtained, for example, by the use of phosgene) are present in the oligoester mixture, and therefore no inorganic salts are present in the subsequent polyester carbonate. It is known that such salts have an adverse effect on the stability of polyester carbonates, because ions can play a catalytic role in the corresponding degradation conditions.

[0051] Preferably, at least one organic base is used, for example an alkylamine, an imidazole (derivative), a guanidine base, for example triazabicyclodecene, DMAP and the corresponding derivatives, a mixture of DBN or DBU and a phosphonium catalyst of formula (VIII) (see below). The catalyst used in process step (II) is most preferably a mixture of 4-(dimethylamino)pyridine (DMAP) and tetrabutylphosphonium acetate.

[0052] If the catalyst is a Lewis acidic transition metal compound, it is preferred to use an alkoxide of a metal of Group IVB or tin of the Periodic Table or a derivative of a metal of Group IVA, a metal oxide or a metal carboxylate. More preferably, the Lewis acidic transition metal compound is selected from titanium butoxide (Ti(OBu) 4), titanium isopropoxide (Ti(OiPr) 4), titanium phenoxide (TiOPh) 4), antimony trioxide, zirconium butoxide (Zr(OBu) 4), dialkyltin dialkoxide, dibutyltin oxide, dibutyltin diester, tin phenoxide, monobutyltin oxide and any mixture thereof. Titanium butoxide is particularly preferred.

[0053] The at least one catalyst is preferably used in an amount of 1 to 5000 ppm, preferably 5 to 1000 ppm, more preferably 20 to 500 ppm, based on the total mass of isophthalic acid and / or terephthalic acid, the diol of formula (3) and the diaryl carbonate of formula (4). If more than one catalyst is used in the reaction, the total amount of these catalysts is preferably 1 to 5000 ppm, preferably 5 to 1000 ppm, more preferably 300 to 700 ppm.

[0054] In process step (III), a vacuum is applied to the mixture obtained from process step (II). As a result, the corresponding aromatic alcohol of the diaryl carbonate used, preferably phenol, is distilled off and the reaction equilibrium is shifted towards the oligoester. The aromatic alcohol is the compound eliminated by the condensation reaction.

[0055] The term "condensation" or "condensation reaction" is known to the person skilled in the art. This is preferably understood to be a reaction in which two molecules (of the same substance or of different substances) combine to form a larger molecule, wherein molecules of a chemically simple substance are eliminated. The compound eliminated in the condensation is removed by vacuum in method step (III). Preferably, therefore, the method according to the invention is characterized in that during method step (III), volatile components having a boiling point lower than the boiling point of the oligoester mixture formed in method step (II) are separated, wherein the pressure is optionally reduced stepwise. When different volatile components are to be separated, it is preferred to separate them stepwise. It is also preferred to separate them stepwise to ensure that the one or more volatile components are separated as completely as possible. The volatile component is one or more chemical compounds eliminated in the condensation, preferably phenol.

[0056] In process step (III), the condensation product is preferably separated at a temperature of 200° C. to 280° C., more preferably at a temperature of 210° C. to 270° C., particularly preferably at a temperature of 220° C. to 265° C. In addition, the vacuum during the separation is preferably 500 mbar to 0.01 mbar. It is particularly preferred to carry out the separation stepwise by reducing the vacuum. The vacuum in the final stage is most preferably 10 mbar to 0.01 mbar.

[0057] The oligoesters thus obtained can be used in process step (a) optionally after further purification. It is preferred here that the oligoesters from step (a) have a number average molecular weight Mn of 500 g / mol to 8000 g / mol, preferably 600 g / mol to 5000 g / mol, more preferably 700 g / mol to 3000 g / mol. Unless otherwise stated, this Mn and / or all other molecular weights in the present invention are preferably determined by gel permeation chromatography in dichloromethane with bisphenol A polycarbonate as a standard. Unless otherwise stated, the molecular weights Mw (weight average) and Mn (number average) of the oligoesters, oligocarbonates, polycarbonates or polyester carbonates used according to the present invention are determined by size exclusion chromatography (gel permeation chromatography, GPC; calibration with BPA polycarbonate according to DIN 55672-1: 2007-08). The calibration is performed using a linear polycarbonate with a known molar mass distribution (e.g. from PSS Polymer Standards Service GmbH, Germany). The method 2301-0257502-09D (German, 2009) of Currenta GmbH & Co. OHG, Leverkusen was used. Dichloromethane was used as the eluent. The column combination consisted of a crosslinked styrene-divinylbenzene resin. The GPC may comprise one or more commercially available GPC columns for size exclusion chromatography connected in series, the selection of which allows sufficient separation of the molar masses of the polymers, in particular the weight-average molar mass M. w The column is an aromatic polycarbonate with a molecular weight of 2000 to 100000 g / mol. The analytical column is usually 7.5 mm in diameter and 300 mm in length. The particle size of the column material is 3 μm to 20 μm.

[0058] Likewise preferably, the oligoesters may have a number average molar mass of 1000 g / mol to 16000 g / mol, more preferably 1200 g / mol to 10000 g / mol, and most preferably 2000 g / mol to 8000 g / mol. n The measurement is preferably carried out by GPC, with calibration using polystyrene in THF. Preferably, polystyrene with a molecular weight range of 500 to 7,000,000 g / mol is used to establish the calibration. GPC is preferably carried out in tetrahydrofuran (preferably THF stabilized with 0.007-0.015% by weight of butylhydroxytoluene), which has been modified with 0.8% by weight of acetic acid. The flow rate is preferably 1 ml / min at 40° C. Furthermore, it is preferred to use a Waters APC TM Column Manager – S and three roots APC TM Column (pore size and ) column combination, where I / d = 150 / 4.6 mm, and filled with particles with a diameter of 2.5 ( and Column) or 1.7μm ( Column)(1μm=1x10 -6 m) of particles. Here, detection is performed by a refractive index detector. The oligoester from step (a) preferably has at least one end group as an end group, which is selected from -OH end groups (e.g. resorcinol end groups), -COOH end groups, isophthalic acid / terephthalic acid-ester-phenol end groups or resorcinol-carbonate-phenol end groups. These end groups can also be present in the form of any mixture. They can also be present in any number or mutual ratio.

[0059] The further chemistry of oligoesters is described, for example, in WO 2005 / 021616 A1. With regard to these chemistry of oligoesters, the content of WO 2005 / 021616 A1 is hereby incorporated by reference into the present disclosure.

[0060] In method step (b), oligomeric carbonates and / or polycarbonates are provided. According to the present invention, the expression "oligomeric" carbonates or "oligomeric" esters is particularly used to distinguish from the expression "poly" carbonates. Those skilled in the art know the definitions of "oligomeric" and "poly". This means in particular that, for example, polycarbonates have a higher number of repeating units than oligomeric carbonates, and therefore a higher molar mass. According to the present invention, when the substance in question itself does not have sufficient mechanical stability, the expression "oligomer" is preferably used. On the contrary, the corresponding "polymer" already has sufficient mechanical stability. According to the present invention, the clear boundary between the two expressions does not seem to be important. However, it is preferred that the oligomeric carbonate from step (b) has a relative solution viscosity of 1.08 to 1.22, preferably 1.11 to 1.22, preferably 1.13 to 1.20. It is also preferred that the polycarbonate from step (b) and step (iii) of the process for preparing a polyester carbonate blend of the present invention has a weight average molecular weight Mw of 24000 g / mol to 40000 g / mol, more preferably 24500 g / mol to 34000 g / mol, most preferably 25000 g / mol to 32000 g / mol, as determined by gel permeation chromatography calibrated with bisphenol A polycarbonate standards using dichloromethane as eluent. It is also preferred that the polycarbonate from step (b) and / or from step (iii) has a relative solution viscosity of greater than 1.20 to 1.36, more preferably greater than 1.22 to 1.35, most preferably greater than 1.27 to 1.34.

[0061] According to the invention, the relative solution viscosity (ηrel; also called etarel) is preferably determined using an Ubbelohde viscometer in dichloromethane at a concentration of 5 g / l at 25° C. The person skilled in the art is familiar with the determination of relative solution viscosity using an Ubbelohde viscometer. According to the invention, this is preferably carried out in accordance with DIN 51562-3; 1985-05. Here, the flow time of the polyester carbonate to be analyzed through the Ubbelohde viscometer is measured in order to subsequently determine the viscosity difference between the polymer solution and its solvent. To this end, the Ubbelohde viscometer is first calibrated by measuring the pure solvents dichloromethane, trichloroethylene and tetrachloroethylene (at least 3 measurements are always carried out here, a maximum of 9 measurements). The actual calibration is then carried out using the solvent dichloromethane. The polymer sample is then weighed and dissolved in dichloromethane, and the flow time of the solution is then measured three times. The average value of the flow time is corrected by the Hagenbach correction method and the relative solution viscosity is calculated.

[0062] Preferably, the oligocarbonate has a phenolic OH group content of 50 ppm to 2500 ppm, preferably 500 to 2400 ppm, particularly preferably 1000 to 2300 ppm. The determination of the proportion of phenolic OH groups is described further below in conjunction with polyester carbonate blends.

[0063] Preferably, the oligocarbonates and / or polycarbonates used in process step (b) do not have any terminal groups of the following formula (301):

[0064]

[0065] Wherein, in formula (301), "*" represents the connection of the structure of formula (301) to oligocarbonates and / or polycarbonates. Therefore, preferably, an activated carbonate source is not used. According to the present invention, this is preferably unnecessary because the reaction in method step (c) is well carried out under defined conditions.

[0066] In the method step (c) according to the invention, the oligoesters in step (a) are reacted with oligocarbonates and / or polycarbonates, wherein the oligoesters are always used in excess relative to the oligocarbonates and / or polycarbonates. Here, 65 to 95% by weight of the oligoesters from step (a) are reacted with 35 to 5% by weight of the oligocarbonates and / or polycarbonates from step (b). Preferably, 70 to 93% by weight, more preferably 75 to 90% by weight of the oligoesters from step (a) are reacted with 30 to 7% by weight, more preferably 25 to 10% by weight of the oligocarbonates and / or polycarbonates from step (b), wherein the weight % is based on the total weight of the oligoesters from step (a) and the oligocarbonates and / or polycarbonates from step (b).

[0067] In step (c) of the method according to the invention, a condensation reaction takes place. The term "condensation reaction" has been defined above. A person skilled in the art knows how such equilibrium reactions can be influenced to obtain the desired product. In particular, according to the invention, it is preferred to carry out step (c) at a reduced pressure relative to the ambient pressure. In this way, the compounds formed in the condensation can be removed by vacuum. Preferably, therefore, the method according to the invention is characterized in that during step (c) of the method, volatile components having a boiling point lower than that of the polyester carbonate prepolymer formed in step (c) of the method are separated, wherein the pressure is optionally reduced stepwise. When different volatile components are separated, it is preferred to choose to separate them stepwise. It is also preferred to choose to separate them stepwise to ensure that the one or more volatile components are separated as completely as possible. The volatile components are preferably one or more chemical compounds eliminated in the condensation, preferably phenol. The volatile components can also be diols of formula (3) that have not yet reacted and / or diaryl carbonates of formula (4) that have not yet reacted and / or low molecular weight oligomers (e.g. dimers or trimers) with correspondingly low boiling points. The person skilled in the art will likewise recognize that corresponding temperatures are optionally required in process step (c) in order to obtain corresponding yields of the polyester carbonate prepolymer.

[0068] Preferably, the oligoesters used according to process step (a) and / or the oligocarbonates and / or polycarbonates used according to process step (b) are amorphous.

[0069] Thus, the process of the invention provides a polyester carbonate prepolymer by reaction of an oligoester with an oligocarbonate and / or a polycarbonate. Thus, in another aspect of the invention, a polyester carbonate prepolymer is provided, which is obtained by the process of the invention for preparing a polyester carbonate prepolymer, said process preferably having all of the above configurations, especially also in combination with the preferred options. Also provided is a polyester carbonate prepolymer comprising

[0070] (A) Ester group of formula (Ia)

[0071]

[0072] wherein R1 is each 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 at which the ester group is incorporated into the polyester carbonate blend,

[0073] (B) Carbonate group of formula (II)

[0074]

[0075] wherein Y is independently a structure of formula (III), (IV), (V) or (VI), wherein

[0076]

[0077] in

[0078] R6 and R7 are each independently hydrogen, C1-C 18 Alkyl, C1-C 18 alkoxy, halogen or in each case optionally substituted aryl or aralkyl, and

[0079] X is a single bond, –CO–, –O–, –S–, C1- to C6-alkylene, C2- to C5-alkylidene, C6- to C 10 -cycloalkylidene, or a C6- to C6- 12 -arylene group,

[0080]

[0081] In these formulae (IV) to (VI), R 3 is in each case C1-C4-alkyl, aralkyl or aryl, preferably methyl or phenyl, most preferably methyl, and

[0082] "*" in each case indicates the position at which the carbonate group in the formula (III), (IV), (V) or (VI) is bonded to the carbonate group in the formula (II),

[0083] m represents the average number of repeating units, and the "*" each represents the position at which a carbonate group is incorporated into the polyester carbonate blend.

[0084] wherein at least a portion of the ester groups (A) are directly linked to at least a portion of the carbonate groups (B) via formula (VII), wherein

[0085]

[0086] wherein Y has the above definition for (B), and (A) represents a connection to an ester group (A), and (B) represents a connection to a carbonate group (B),

[0087] And it is also characterized in that the polyester carbonate prepolymer contains a mole % of carbon atoms indicated by the arrow in formula (Ia) that is greater than the mole % of carbon atoms indicated by the arrow in formula (VII);

[0088] wherein R1, n and "*" have the above definitions, and

[0089] wherein (A), Y and (B) have the above-mentioned definitions. The polyester carbonate prepolymer is preferably obtained by the process according to the invention for preparing a polyester carbonate prepolymer, said process preferably having all of the above-mentioned configurations, in particular also in combination with the preferences.

[0090] The determination of the formulae (Ia) and (VII) is described below in particular with respect to the polyester carbonate blends according to the invention. A person skilled in the art will also be able to apply all details relating to the blends to the polyester carbonate prepolymers, as far as this is applicable and desirable.

[0091] The polyester carbonate prepolymer of the present invention has a higher molar mass than the starting oligoester in step (a), but its molar mass depends largely on the oligocarbonate and / or polycarbonate used. The polyester carbonate prepolymer also has the structure of formula (7) through the reaction:

[0092]

[0093] wherein R1 has the meaning given for formula (I), Y has the meaning given below (Y is derived from the bisphenol used to prepare the oligocarbonate and / or polycarbonate), and "..." denotes the logical continuation of the chain (especially further esters formed from the oligomers from step (a) or further carbonates formed from the oligocarbonate and / or polycarbonate from step (b)). Formula (7) shows an ester bond between isophthalic acid / terephthalic acid and the bisphenol of the oligocarbonate and / or polycarbonate.

[0094] In particular, the polyester carbonate prepolymers according to the invention (e.g. as described for the process according to the invention) are prepared by reacting an oligoester as described above with an oligocarbonate and / or polycarbonate, wherein the oligoester is always used in excess relative to the oligocarbonate and / or polycarbonate. Preferably, 65 to 95% by weight of the oligoester (e.g. as described above from step (a)) is reacted with 35 to 5% by weight of the oligocarbonate and / or polycarbonate (e.g. as described above from step (b)). Preferably, 70 to 93% by weight, more preferably 75 to 90% by weight of the oligoester (e.g. as described above from step (a)) is reacted with 30 to 7% by weight, more preferably 25 to 10% by weight of the oligocarbonate and / or polycarbonate (e.g. as described above from step (b)), wherein the % by weight is based on the total weight of the oligoester and the oligocarbonate and / or polycarbonate. Therefore, the polyester carbonate prepolymers according to the invention preferably have different weight ratios of structures containing ester groups and structures containing carbonate groups.

[0095] Furthermore, the polyester carbonate prepolymers according to the invention preferably do not contain any methyl 2-hydroxybenzoate. Traces of this compound can be detected in the prepolymers, for example by NMR spectroscopy. When an activated carbonate source (e.g. an oligocarbonate and / or polycarbonate having end groups of the formula (301)) is used to prepare the polyester carbonate prepolymers, they may remain in the polyester carbonate prepolymers. Likewise preferably, the polyester carbonate prepolymers according to the invention therefore also do not have any end groups of the formula (301).

[0096] According to the invention, it has been found that the reaction between the oligoester and the oligocarbonate and / or the polycarbonate takes place. It can be seen from this that the resulting polyester carbonate prepolymer is essentially transparent. The term "transparent" is preferably used here, as described for the polyester carbonate blend.

[0097] According to the invention, it has been found that the resulting polyester carbonate prepolymers are suitable for providing polyester carbonate blends by mixing and / or reacting with another polycarbonate, which blends meet the high requirements for the mechanical and optical properties of standard polycarbonates on the one hand, but at the same time have inherent weathering stability. Without wishing to be bound by theory, the polyester carbonate prepolymers appear to act as compatibilizers, which enable a homogeneous mixture between ester groups and polycarbonate. In particular, the polyester carbonate prepolymers according to the invention are suitable for preparing polyester carbonate blends in the process according to the invention.

[0098] Another aspect of the present invention provides a method for preparing a polyester carbonate blend, comprising the steps of:

[0099] (i) providing a polyester carbonate prepolymer according to the present invention, which preferably has all of the above configurations and combinations of the preferred items,

[0100] (ii) providing a polycarbonate having a weight average molecular weight Mw of 24,000 to 40,000 g / mol, more preferably 24,500 to 34,000 g / mol, most preferably 25,000 to 32,000 g / mol, as determined by gel permeation chromatography using dichloromethane as the eluent and calibrated against bisphenol A polycarbonate standards,

[0101] (iii) converting the polyester carbonate prepolymer from step (i) and the polycarbonate from step (ii) into a molten state and mixing 5 to 25 wt. % of the polyester carbonate prepolymer with 95 to 75 wt. % of the polycarbonate in the molten state to obtain a polyester carbonate blend, wherein the wt. % is based on the total weight of the polyester carbonate prepolymer from step (i) and the polycarbonate from step (ii).

[0102] It will be clear to the skilled person that method step (i) preferably comprises method steps (a) to (c) described above.

[0103] The polycarbonate used in process step (ii) may be the same as or different from the polycarbonate used arbitrarily in step (b). However, the method for preparing the polyester carbonate blend according to the invention differs from the method for preparing the polyester carbonate prepolymer according to the invention in that, when preparing the polyester carbonate blend according to the invention, on the one hand, polycarbonate (instead of oligomeric polycarbonate) must be used and, on the other hand, the polycarbonate is used in excess relative to the polyester carbonate prepolymer. The use of polycarbonate (instead of oligomeric polycarbonate) in process step (ii) is necessary because only in this way can good mechanical properties of the polyester carbonate blend be ensured, preferably comparable to those of standard polycarbonates. The polycarbonate is preferably an aromatic polycarbonate. Most preferably, the polycarbonate is a polycarbonate having repeating units of formula (II)

[0104]

[0105] wherein Y is independently a structure of formula (III), (IV), (V) or (VI), wherein

[0106]

[0107] in

[0108] R6 and R7 are each independently hydrogen, C1-C 18 -alkyl, C1-C 18 - alkoxy, halogen or in each case optionally substituted aryl or aralkyl, and

[0109] X is a single bond, –CO–, –O–, –S–, C1- to C6-alkylene, C2- to C5-alkylidene, C6- to C 10 -cycloalkylidene, or a C6- to C6- 12 -arylene group,

[0110]

[0111] In these formulae (IV) to (VI), R 3 is in each case C1-C4-alkyl, aralkyl or aryl, preferably methyl or phenyl, most preferably methyl, and

[0112] "*" in each case indicates the position at which the carbonate group in the formula (III), (IV), (V) or (VI) is bonded to the carbonate group in the formula (II),

[0113] m denotes the number of repeating units (m here can be calculated via the specific molecular weight of the polycarbonate used). Most preferably, the polycarbonate from process step (b) is based on bisphenol A.

[0114] In method step (iii), the polyester carbonate prepolymer from step (i) and the polycarbonate from step (ii) are first converted into a molten state. This can be achieved by providing energy in a manner known to the person skilled in the art. The temperature selected here should be a temperature at which the two components are in a molten state. In particular, the temperature selected should therefore be above the glass transition temperature and / or the melting point of the polyester carbonate prepolymer and the polycarbonate, preferably above the glass transition temperature. During method step (iii), this temperature should be maintained at least to mix the components in a molten state.

[0115] In process step (iii), the polyester carbonate prepolymer is used in a deficit relative to the polycarbonate. Preferably, 8 to 35% by weight, more preferably 10 to 30% by weight, most preferably 15 to 25% by weight of the polyester carbonate prepolymer is mixed with 92 to 65% by weight, more preferably 90 to 70% by weight, most preferably 85 to 75% by weight of the polycarbonate in the molten state, the % by weight being based on the total weight of the polyester carbonate prepolymer from step (i) and the polycarbonate from step (ii).

[0116] In method step (iii), in one embodiment, a reaction may take place between the polyester carbonate prepolymer and the polycarbonate. This is in particular a condensation reaction as described in detail above. In another embodiment, no reaction takes place between the two components. This results in a physical mixture. However, the polyester carbonate blend according to the invention is in any case a single-phase homogeneous mixture. In particular, according to the invention, the term "homogeneous mixture" is understood as meaning that there are no two discrete phases that are distinguishable from each other in terms of phase morphology, but only one homogeneous phase. This can be verified in particular by the transparency of the polyester carbonate blend according to the invention. In the context of the present invention, a "transparent" blend is understood as a blend having a transmittance (TVIS transmittance) of more than 20% in the VIS region of the spectrum (380 to 780 nm) measured according to DIN ISO 13468-2:2006 (D65, 10 °, sample thickness: 4 mm). It is also preferred that they have a haze of less than 10% measured according to ASTM D1003:2013. This means in particular that the blend has visual transparency, i.e., shows the background, and can therefore be used as, for example, a transparent cover.

[0117] This means that, according to the invention, the term "blend" encompasses both physical mixtures and mixtures in which at least a portion of the polyester carbonate prepolymer has reacted with the polycarbonate.

[0118] The person skilled in the art is aware of methods which can influence whether a reaction occurs in method step (iii). Since the reaction is preferably a condensation reaction, the above details apply analogously here. It is particularly preferred that method step (iii) is carried out at a reduced pressure relative to the ambient pressure. In this way, the compounds formed in the condensation can be removed by vacuum. It is therefore preferred that the method according to the invention is characterized in that during method step (iii), volatile components having a boiling point lower than that of the polyester carbonate blend formed in method step (ii) are separated, wherein the pressure is optionally reduced stepwise. When different volatile components are to be separated, it is preferred to separate them stepwise. It is also preferred to separate them stepwise to ensure that the one or more volatile components are separated as completely as possible. Volatile components are one or more chemical compounds which are eliminated in the condensation.

[0119] Likewise, in process step (iii), catalysts familiar to the person skilled in the art can be used. However, the process according to the invention is preferably carried out in the absence of a catalyst. This has the advantage that the catalyst does not need to be separated from the polyester carbonate blend obtained or does not remain therein. Depending on the catalyst, this can affect the stability of the polyester carbonate blend. The process according to the invention can also be carried out in the presence of a catalyst, particularly preferably in the presence of a basic catalyst.

[0120] Useful catalysts include all inorganic or organic basic compounds, for example hydroxides, carbonates, halides, phenolates, diphenolates, fluorides, acetates, phosphates, hydrogenphosphates, borates of lithium, sodium, potassium, cesium, calcium, barium, magnesium, nitrogen bases and phosphorus bases, for example tetramethylammonium hydroxide, tetramethylammonium acetate, tetramethylammonium fluoride, tetramethylammonium tetraphenylborate, tetraphenylphosphonium fluoride, tetraphenylphosphonium tetraphenylborate, dimethyldiphenylammonium hydroxide, tetraethylammonium hydroxide, hexadecyltrimethylammonium tetraphenylborate, hexadecyltrimethylammonium phenolate, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) or guanidine systems, 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'-hexylidenedi-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7,7'-decylidenedi-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7,7'-dodecane 1,5,7-triazabicyclo[4.4.0]dec-5-ene or phosphazene, for example phosphazene base P1-t-Oct = tert-octyliminotris(dimethylamino)phosphine, phosphazene base P1-t-Butyl = tert-butyliminotris(dimethylamino)phosphine, BEMP = 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diaza-2-phosphine.

[0121] Especially suitable are phosphonium catalysts of formula (VIII):

[0122]

[0123] Wherein Ra, Rb, Rc and Rd can be the same or different C1-C10 alkyl, C6-C14 aryl, C7-C15 aralkyl or C5-C6 cycloalkyl, preferably methyl or C6-C14 aryl, particularly preferably methyl or phenyl, and X- can be an anion, such as hydroxide, sulfate, hydrogensulfate, bicarbonate, carbonate or halide, preferably chloride or alkoxide or aryloxide of formula -OR, wherein R can be C6-C14 aryl, C7-C15 aralkyl or C5-C6 cycloalkyl, preferably phenyl.

[0124] Particularly preferred catalysts are tetraphenylphosphonium chloride, tetraphenylphosphonium hydroxide and tetraphenylphosphonium phenolate; tetraphenylphosphonium phenolate is particularly preferred. Likewise preferred is tetrabutylphosphonium acetate.

[0125] The amount of these catalysts is preferably 10 -2 Up to 10 -8mol, based on 1 mol of polyester carbonate prepolymer. The amount of the basic salt used as a co-catalyst may be 1 to 500 ppb, preferably 5 to 300 ppb, particularly preferably 5 to 200 ppb.

[0126] Method step (iii) is preferably carried out at a temperature of 280°C to 400°C, preferably 300°C to 390°C, more preferably 305°C to 350°C and further preferably 310°C to 340°C. It is also preferred that method step (iii) is carried out at a pressure of 0.001 mbar to 50 mbar, more preferably 0.005 to 40 mbar, even more preferably 0.02 to 30 mbar, further preferably 0.03 to 5 mbar. It is also preferred that no vacuum is applied in method step (iii). It is particularly preferred that method step (iii) is carried out at a combination of the above-mentioned temperature and the above-mentioned pressure. It is particularly preferred that the components in method steps (i) and (ii) are first in solid form. In method step (iii), they are preferably converted into a melt by rising temperature conditions. The above-mentioned temperature here is preferably the final temperature. The mixing in method step (iii) is preferably carried out at this temperature.

[0127] In method step (iii), the mixing of the components in the molten state can be achieved in a manner known to the person skilled in the art. It should be distinguished here whether it is clearly desired that the components react or more likely that mixing should be carried out. However, according to the invention, it is not excluded that a reaction may occur between the components in the latter case. Mixing is preferably achieved by laminar mixing of the components in the molten state.

[0128] Preferred reactors for process step (iii) are suitable for processing high viscosity materials, provide sufficient residence time and good mixing, and subject the polyester carbonate prepolymer and polycarbonate to an optionally required vacuum. According to the invention, for process step (iii) preferably an extruder, in particular a twin-shaft extruder, or a thin film evaporator is used. Thin film evaporators suitable in principle for carrying out the process according to the invention are described, for example, in EP 3 318 311 A1, EP 1 792 643 A1, DE 195 35 817 A1, DE 10 2012 10 3 749 A1, DE 2011 493 A1 or DD-226 778 B1 or in the publications [1] “Platzer (ed.): Polymerization Kinetics and Technology, Advances in Chemistry; American Chemical Society: Washington, DC, 1973, pp. 51 to 67: Fritz Widmer: Behaviour of Viscous Polymers during Solvent Stripping or Reaction in an Agitated Thin Film; Swiss Federal Institute of Technology, 1983, pp. 1 to 12. Technology, Zurich, Switzerland", wherein DE19535817A1, DD-226778B1 or EP3318311A1 or [1], the thin film evaporator disclosed in Figure 7, page 58 and Figure 9, page 60 is particularly suitable for implementing the method according to the present invention. In addition, according to the present invention, reactors according to EP460466A1, EP528210A1, EP638354A1, EP715881A2, EP715882A2, EP798093A2 or reactors according to EP329092A1, according to EP517068A1 or EP1436073A1 and reactors according to EP222599A2 can also be used.

[0129] The time for mixing the components in process step (iii) depends in a manner known to the person skilled in the art on the reactor or reactors used. In principle, short times are preferred here.

[0130] Process step (iii) can be carried out without at least one stabilizer. However, it has been found to be advantageous if at least one stabilizer is present in process step (iii). Likewise, process step c) can also be carried out in the presence of at least one stabilizer. If at least one stabilizer is to be used in both process step c) and process step (iii), the stabilizers may be identical or different in both process steps.

[0131] Such stabilizers are also often referred to as stabilizing additives. These stabilizing additives that can be used in the present invention are primarily used to inhibit the transesterification reaction between the individual oligomers or polymers. However, the actual reaction between the oligomers or polymers can also be optionally inhibited here. The suitability of a particular compound for use as a stabilizer in the present invention and the determination of a suitable amount of such a stabilizer in the present invention can be determined by preparing a mixture consisting of a polyester carbonate blend and an additive and determining the effect on melt viscosity, relative solution viscosity and / or transesterification activity. Taking into account the embodiment in which a vacuum is applied in method step (iii), the smaller the increase in molecular weight (e.g. measured by relative solution viscosity), the more suitable the compound is as a stabilizer in the present invention. In particular, if no vacuum is applied in method step (iii), the smaller the decrease in molecular weight (e.g. measured by relative solution viscosity), the greater the suitability of the compound as a stabilizer in the present invention. The transesterification activity of the compound can be measured by 13 C-NMR spectroscopy and comparison of the different ester bands (see also the method description in the Examples section). The more carbon atoms indicated by the arrows in formula (Ia), the more effective the compound in question is, especially as a stabilizer in the context of the present invention.

[0132] Bronsted acids are particularly useful here. Specific examples of useful Bronsted acid compounds include phosphoric acid, phosphorous acid, hypophosphorous acid, pyrophosphoric acid, polyphosphoric acid, boric acid, hydrochloric acid, hydrobromic acid, sulfuric acid, sulfurous acid, adipic acid, azelaic acid, dodecanoic acid, L-ascorbic acid, aspartic acid, benzoic acid, formic acid, acetic acid, citric acid, glutamic acid, salicylic acid, nicotinic acid, fumaric acid, maleic acid, oxalic acid, benzenesulfinic acid, toluenesulfinic acid and sulfonic acids, such as benzenesulfonic acid, p-toluenesulfonic acid, trichloromethanesulfonic acid, naphthalenesulfonic acid, sulfonated polystyrene and methacrylate sulfonated styrene copolymers. Phosphoric acid, phosphorous acid and their salts and esters are particularly preferred here. Examples of preferred salts are hydrogen phosphates, such as zinc hydrogen phosphate or calcium hydrogen phosphate. Their usage is preferably in an amount of 0.0001 to 0.1, especially 0.0001 to 0.05 weight percent based on the total composition weight. These acid compounds can be used alone or in combination. The acids, esters and salts can also be used in the form of masterbatches based on polycarbonates or polyesters or polyester carbonates.

[0133] The stabilizer used may also be an epoxy compound having at least one epoxy group in the molecule. The amount thereof may be 0.001% to 0.5% by weight, preferably 0.005% to 0.2% by weight, based on the total weight of all components used. As described above, specific examples of useful epoxy compounds include epoxidized soybean oil, epoxidized linseed oil, phenyl glycidyl ether, allyl glycidyl ether, tert-butylphenyl glycidyl ether, 3,4-epoxycyclohexanecarboxylic acid 3,4-epoxycyclohexyl methyl ester, 3,4-epoxy-6-methylcyclohexanecarboxylic acid 3,4-epoxy-6-methylcyclohexanecarboxylic acid 2,3-epoxycyclohexyl methyl ester, 3,4-epoxycyclohexanecarboxylic acid 4-(3,4-epoxycyclohexanecarboxylic acid) ester. 6-Methylcyclohexyl)butyl ester, 3,4-epoxycyclohexyl oxirane, 3,4-epoxycyclohexanecarboxylic acid cyclohexyl methyl ester, 6-methylcyclohexanecarboxylic acid 3,4-epoxy-6-methylcyclohexyl methyl ester, bisphenol A diglycidyl ether, tetrabromobisphenol A glycidyl ether, phthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, dicyclopentadienyl ether, diethylene glycol, adipate dicyclohexyl ester, butadiene diepoxide, tetraphenyl oxirane, Octyl epoxyphthalate, epoxidized polybutadiene, 3,4-dimethyl-1,2-epoxychlorohexane, 3-methyl-5-tert-butyl-1,2-epoxycyclohexane, 2,2-dimethyl-3,4-epoxycyclohexanecarboxylic acid octadecyl ester, 2,2-dimethyl-3,4-epoxycyclohexanecarboxylic acid n-butyl ester, 2-methyl-3,4-epoxycyclohexanecarboxylic acid cyclohexyl ester, 2-isopropyl-3,4-epoxy-5-methylcyclohexanecarboxylic acid n-butyl ester, 3,4-epoxycyclohexanecarboxylic acid octadecyl ester Alkyl esters, 2-ethylhexyl 3',4'-epoxycyclohexanecarboxylate, 4,6-dimethyl-2,3-epoxycyclohexyl 3',4'-epoxycyclohexanecarboxylate, 4,5-epoxytetrahydrophthalic anhydride, 3-tert-butyl-4,5-epoxytetrahydrophthalic anhydride, diethyl 4,5-epoxy-cis-1,2-cyclohexanedicarboxylate and di-n-butyl 3-tert-butyl-4,5-epoxy-cis-1,2-cyclohexanedicarboxylate; these epoxy compounds can be used alone or in combination. These epoxy compounds can also be used together with the above-mentioned acid compounds.

[0134] In addition, alkyl phosphates such as mono-, di- and tri-hexyl phosphates, triisooctyl phosphates and trinonyl phosphates can be used as stabilizers. The alkyl phosphates used are preferably triisooctyl phosphates (tri-2-ethylhexyl phosphate). Mixtures of different mono-, di- and tri-alkyl phosphates can also be used. These mixtures can be used in an amount of 0.001 to 0.1% by weight, preferably 0.005 to 0.05% by weight, based on the total weight of all components used.

[0135] Likewise, at least one other additive (which is different from the above-mentioned optionally present stabilizer) may also be present during method step (iii) and / or method step c). Such additives commonly added to polycarbonates are in particular heat stabilizers or processing stabilizers, antioxidants (in particular phenolic antioxidants), release agents, flame retardants, anti-drip agents, UV absorbers, infrared absorbers, antistatic agents, fluorescent brighteners, fillers, light scatterers, hydrolysis stabilizers and / or additives for laser marking, in particular in amounts commonly used for polycarbonate-based compositions. Such additives are described, for example, in EP0839623 A1, WO 96 / 15102 A1, EP 0500496 A1 or "Plastics Additives Handbook", Hans Zweifel, 5th edition, 2000, Hanser Verlag, München. These additives may be added individually or as a mixture.

[0136] The heat stabilizers or processing stabilizers used may be, for example, phosphites and phosphonites, and phosphines. Examples include triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl) phosphite, trilauryl phosphite, tri(octadecyl) phosphite, pentaerythritol distearyl diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, pentaerythritol diisodecyl diphosphite, pentaerythritol dibis(2,4-di-tert-butylphenyl) phosphite, pentaerythritol dibis(2,4-diisopropylphenyl) phosphite, pentaerythritol diphosphite Pentaerythritol diphosphite bis(2,6-di-tert-butyl-4-methylphenyl) ester, pentaerythritol diphosphite diisodecyl ester, pentaerythritol diphosphite bis(2,4-di-tert-butyl-6-methylphenyl) ester, pentaerythritol diphosphite bis(2,4,6-tri(tert-butylphenyl) ester, sorbitol triphosphite tristearyl ester, 4,4'-biphenyl diphosphite tetra(2,4-di-tert-butylphenyl) ester, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenzo[d,g]- 1,3,2-dioxaphosphocene, bis(2,4-di-tert-butyl-6-methylphenyl) methyl phosphite, bis(2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyldibenzo[d,g]-1,3,2-dioxaphosphocene, 2,2',2"-nitrilo[triethyltri(3,3',5,5'-tetra-tert-butyl-1,1'-biphenyl-2,2'-diyl)phosphite Acid ester], (3,3',5,5'-tetra-tert-butyl-1,1'-biphenyl-2,2'-diyl) phosphite 2-ethylhexyl ester, 5-butyl-5-ethyl-2-(2,4,6-tri-tert-butylphenoxy)-1,3,2-dioxaphospharidine, pentaerythritol diphosphite bis(2,6-di-tert-butyl-4-methylphenyl) ester, triphenylphosphine (TPP), trialkylphenylphosphine, bisdiphenylphosphine ethane or trinaphthylphosphine. In particular, triphenylphosphine (TPP), 168 (tris(2,4-di-tert-butylphenyl) phosphite) and tris(nonylphenyl) phosphite or a mixture thereof.

[0137] Preferred phenolic antioxidants include alkylated monophenols, alkylated sulfanylphenols, hydroquinone and alkylated hydroquinone. 1010 (pentaerythritol 3-(4-hydroxy-3,5-di-tert-butylphenyl) propionate; CAS: 6683-19-8) and Irganox (2,6-di-tert-butyl-4-(octadecyloxycarbonylethyl)phenol).

[0138] These heat stabilizers or processing stabilizers and / or phenolic antioxidants may be used in an amount of 0.5 to 0.001% by weight, based on the total weight of all components present. These may be used alone or in admixture with the above-mentioned additives. They may be added directly or as a masterbatch.

[0139] Therefore, the method for preparing a polyester carbonate blend according to the present invention provides a polyester carbonate blend, which is a physical mixture and / or reaction product formed by a polyester carbonate prepolymer and a polycarbonate. Therefore, the present invention also provides a polyester carbonate blend obtained by the method for preparing a polyester carbonate blend according to the present invention, which preferably has the above configuration or a combination of all preferred items.

[0140] Another aspect of the present invention provides a polyester carbonate blend comprising

[0141] (A) Ester group of formula (Ia)

[0142]

[0143] wherein R1 is each 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 at which the ester group is incorporated into the polyester carbonate blend,

[0144] (B) Carbonate group of formula (II)

[0145]

[0146] wherein Y is independently a structure of formula (III), (IV), (V) or (VI), wherein

[0147]

[0148] in

[0149] R6 and R7 are each independently hydrogen, C1-C 18 -alkyl, C1-C 18 - alkoxy, halogen or in each case optionally substituted aryl or aralkyl, preferably hydrogen, and

[0150] X is a single bond, –CO–, –O–, –S–, C1- to C6-alkylene, C2- to C5-alkylidene, C6- to C 10 -cycloalkylidene, or a C6- to C6- 12 -arylene, preferably a single bond, C2- to C5-alkylidene or C6- to C 10 - cycloalkylidene, particularly preferably isopropylidene,

[0151]

[0152] In these formulae (IV) to (VI), R 3 is in each case C1-C4-alkyl, aralkyl or aryl, preferably methyl or phenyl, most preferably methyl, and

[0153] "*" in each case indicates the position at which the carbonate group in the formula (III), (IV), (V) or (VI) is bonded to the carbonate group in the formula (II),

[0154] m represents the average number of repeating units, and the "*" each represents the position at which a carbonate group is incorporated into the polyester carbonate blend.

[0155] wherein at least a portion of the ester groups (A) are directly linked to at least a portion of the carbonate groups (B) via formula (VII), wherein

[0156]

[0157] wherein Y has the above definition for (B), and (A) represents a connection to an ester group (A), and (B) represents a connection to a carbonate group (B),

[0158] wherein the relative solution viscosity of the polyester carbonate blend is at least 1.19 and at most 1.40, preferably 1.20 to 1.38, more preferably 1.21 to 1.35, most preferably 1.22 to 1.33,

[0159] Characterized in that the polyester carbonate blend contains a mole % of carbon atoms indicated by the arrow in formula (Ia) that is greater than the mole % of carbon atoms indicated by the arrow in formula (VII);

[0160] wherein R1, n and "*" have the above definitions, and

[0161] wherein (A), Y and (B) have the above definitions.

[0162] Like the polyester carbonate prepolymers, the polyester carbonate blends according to the invention are also characterized in that isophthalic acid / terephthalic acid is bonded via esters to repeating units of polycarbonate (optionally also oligocarbonate, for example formed from unreacted groups from process step (c) or by reaction in process step (c)) (see formula (VII). Formula (VII) is explained in detail above by formula (7).

[0163] The presence of the structure of formula (VII) can be determined by NMR. This is exemplified by direct bonding of the bisphenol units to the isophthalic acid and / or terephthalic acid units. The bonding is an ester bond. The presence of this bonding can be determined by 13The residues were determined by C-NMR spectroscopy, which was performed by determining the chemical shift of the carbonyl carbon atom indicated by the arrow in formula (VIIa).

[0164]

[0165] The experimental section describes the synthesis of a model compound formed from bisphenol A and isophthalic acid / terephthalic acid in order to 13 The position of the carbon indicated by the arrow in formula (VIIa) was found / calibrated in C-NMR.

[0166] The polyester carbonates comprising ester groups (A) and (B) prepared by the phase interface process do not have the structure (VII) (see Figure 2 ). In such reactions, OH-terminated oligoesters are converted into carbonates with bisphenols (usually bisphenol A) or corresponding oligocarbonates by reaction with phosgene. This means, for example, that there is always one resorcinol unit bonded directly to a BPA unit via a carbonate group. The same applies to the polyester carbonates of DE 60212172 T2.

[0167] The carbon atom indicated by the arrow in the above formula (VII) can be formed by reacting the chain end of the oligoester with the oligocarbonate and / or polycarbonate in method step (c) and / or (iii). Alternatively, it can also be formed by an ester exchange reaction in method step (c) and / or (iii). This ester exchange reaction is basically undesirable because it reduces the inherent UV absorption capacity of the polymer. These esters must have a certain block length so that the resulting product has inherent weathering stability. Nevertheless, the polyester carbonate blend according to the present invention always has a certain detectable proportion of the carbon atoms. It will be understood by those skilled in the art that the above formula (VII) is shown once with an arrow and once without an arrow. For better understanding, the formula (VII) with an arrow can also be expressed as formula (VIIx). Therefore, it is important for the present invention that the mole % of the carbon atom indicated by the arrow in the formula (Ia) in the polyester carbonate blend is greater than the mole % of the carbon atom indicated by the arrow in the formula (VII). It will be understood by those skilled in the art that the above formula (Ia) is shown once with an arrow and once without an arrow. For better understanding, the formula (Ia) with an arrow can also be represented as formula (Iax). By the ratio between the different ester compounds, it can be ensured that the resulting polyester carbonate blend has both good mechanical properties and inherent weathering stability.

[0168] The ratio of the mole % of carbon atoms indicated in formula (Iax) and (VIIx) is preferably expressed by 13C-NMR spectroscopy is used for determination. For this purpose, the polyester carbonate blend is preferably dissolved in CDCl3. It is further preferred to use tetramethylsilane as a standard. It has been found that a 600 MHz NMR spectrometer is sufficient to distinguish the individual carbon signals of formula (Iax) and (VIIx). The chemical shift of the carbon signal of formula (VIIx) depends on the repeating units of the oligocarbonate and / or polycarbonate. If oligocarbonates and / or polycarbonates based on bisphenol A are used, the corresponding signals can be found at about 164-165 ppm (see also the experimental section). When the diol of formula (3) is resorcinol, the chemical shift of the carbon atom indicated in formula (Iax) is generally 163-164 ppm. In order to determine the ratio of the molar % of carbon atoms, the area under the signal is integrated and expressed as a ratio to each other. This is a method known to those skilled in the art.

[0169] It will be clear to the skilled person that ester groups (A) and carbonate groups (B) can be repeated in the polyester carbonate blend, respectively. Likewise, it will be clear to the skilled person that n and m and the number of ester groups (A) and / or carbonate groups (B) must be selected so as to produce a corresponding solution viscosity of the polyester carbonate blend. In contrast, the skilled person will be able to derive the number average molecular weight from the solution viscosity. It will also be clear to the skilled person that n and m are derived based on such number average molecular weight and the ratio of ester groups (A) and / or carbonate groups (B). In particular, the skilled person will be able to estimate the order of magnitude of the average number of repeating units n and / or m based on the starting material. The skilled person will be able to estimate the possible effects of the reaction in method step (iii) on n and / or m. Preferably, m in formula (II) is at least 5, preferably 8 to 300, more preferably 10 to 250, and most preferably 25 to 200. Here, preferably, the polyester carbonate blends according to the invention have a proportion of ester groups (A) of 5 to 25% by weight, more preferably 8 to 23% by weight, most preferably 10 to 20% by weight, based on the total weight of ester groups (A) and carbonate groups (B). Likewise preferably, the polyester carbonates according to the invention consist of at least 80% by weight, more preferably at least 90% by weight, most preferably at least 95% by weight of units of the formula (Ia) and (II).

[0170] It is obvious to the person skilled in the art that the term "blend" is preferably to be understood here as meaning that the polyester carbonate according to the invention comprises a mixture of different polymers. These polymers can be polyester carbonates but also pure polycarbonates. This is particularly evident when the polyester carbonate blend according to the invention is prepared by the method according to the invention for preparing a polyester carbonate blend. The polyester carbonate blend according to the invention preferably further comprises component (X), which is a polycarbonate. This is more preferably a polycarbonate having repeating units of formula (II), as explained in detail above. The person skilled in the art will be able to transfer in particular the details relating to the method according to the invention for preparing a polyester carbonate blend to the polyester carbonate blend according to the invention.

[0171] Furthermore, the polyester carbonate blends of the present invention preferably do not contain any methyl 2-hydroxybenzoate. For example, traces of such compounds can be detected in the blends by NMR spectroscopy. When an activated carbonate source (e.g., a polycarbonate having end groups of formula (301)) is used to prepare the polyester carbonate blends, they may remain in the polyester carbonate blends. Likewise, the polyester carbonate blends of the present invention therefore also do not have any end groups of formula (301).

[0172] Preferably, the polyester carbonate blend according to the invention is characterized in that the relative solution viscosity of the polyester carbonate blend is at least 1.19 to a maximum of 1.40, preferably 1.20 to 1.38, more preferably 1.21 to 1.35, most preferably 1.22 to 1.33. This relative solution viscosity allows the polyester carbonate blend to have good processability, for example by injection molding. This relative solution viscosity also enables it to exhibit good mechanical properties for use in interesting areas of application, such as automotive exterior areas. The polyester carbonate blend has high stability and has inherent weathering stability.

[0173] Likewise, the polycarbonate blends of the present invention preferably have a phenolic OH group content of 100 ppm to 1200 ppm, preferably 150 ppm to 1000 ppm, more preferably 200 ppm to 800 ppm. Alternatively, the polyester carbonate blends of the present invention preferably have a phenolic OH group content of 0 ppm to 500 ppm, preferably greater than 50 ppm to 350 ppm, more preferably greater than 80 ppm to 800 ppm. The phenolic OH group content is preferably determined by infrared spectroscopy. It can also be determined by 1 H-NMR determination. However, the signals here may overlap. Therefore, the phenolic OH group content is preferably determined by infrared spectroscopy. For this purpose, the polyester carbonate blend is preferably dissolved in dichloromethane (2 g / 50 ml) and the wavelength is evaluated at 3583 cm -1 The calibration of the infrared device required for this is known to the person skilled in the art.

[0174] Both the polyester carbonate prepolymers according to the invention and the polyester carbonate blends according to the invention may contain rearranged structures (for example the Friis rearranged structures known to the person skilled in the art). This may be due, on the one hand, to the fact that the reaction takes place in the melt in the process according to the invention. As is known to the person skilled in the art, corresponding structures can be formed under melt transesterification conditions. Furthermore, the oligocarbonates and / or polycarbonates used according to the invention may also already contain such Friis structures. According to the invention, it has been found that these Friis rearranged structures have no particularly adverse effect on the properties of the polyester carbonate prepolymers and / or blends according to the invention.

[0175] In particular, the polyester carbonate prepolymers according to the invention and / or the polyester carbonate blends according to the invention and / or the oligocarbonates and / or polycarbonates used may contain at least one, preferably a plurality of, the following structures (4y) to (7y):

[0176]

[0177] The benzene rings may be independently monosubstituted or disubstituted by C1-C8 alkyl, halogen, preferably C1 to C4 alkyl, more preferably methyl, and X is a single bond, C1 to C6 alkylene, C2 to C5 alkylidene or C5 to C6 cycloalkylidene, preferably a single bond or C1 to C4 alkylene, particularly preferably isopropylidene. The total amount of structural units (4y) to (7y) (determined after saponification) is usually 10 ppm to 1000 ppm, preferably greater than 10 ppm to 900 ppm, more preferably 50 to 850 ppm, preferably 80 to 800 ppm.

[0178] In order to determine the amount of rearranged structures, the respective polymers were completely saponified, thereby forming the corresponding degradation products of the formulae (4ya) to (7ya), the amount of which was determined by HPLC. The structures (4ya) to (7ya) are given by way of example using polycarbonates containing bisphenol A. (This can be achieved, for example, as follows: a polycarbonate sample is saponified under reflux with sodium methoxide. The corresponding solution is acidified and concentrated to dryness. The dry residue is dissolved in acetonitrile and the phenolic compounds of the formulae (4ya) to (7ya) are determined by HPLC with UV detection):

[0179]

[0180] The amount of the compound of the formula (4ya) released here is preferably from 20 to 800 ppm, more preferably from 25 to 700 ppm, particularly preferably from 30 to 500 ppm.

[0181] The amount of the compound of the formula (5ya) released here is preferably 0 (ie below the detection limit of 10 ppm) to 100 ppm, more preferably 0 to 80 ppm, particularly preferably 0 to 50 ppm.

[0182] The amount of the compound of the formula (6ya) released here is preferably 0 (ie below the detection limit of 10 ppm) to 800 ppm, more preferably 10 to 700 ppm, particularly preferably 20 to 600 ppm, most preferably 30 to 350 ppm.

[0183] The amount of the compound of the formula (7ya) released here is preferably from 0 (ie below the detection limit of 10 ppm) to 300 ppm, preferably from 5 to 250 ppm, particularly preferably from 10 to 200 ppm.

[0184] In another aspect of the present invention, the use of a polyester carbonate prepolymer according to the present invention for compatibilizing an oligoester comprising a structure of formula (I) with a polycarbonate is described, the polyester carbonate prepolymer preferably having a combination of all the above configurations and / or preferences,

[0185]

[0186] wherein R1 is each independently a hydrogen atom, a halogen or an alkyl group having 1 to 4 carbon atoms, and n is at least 4.

[0187] As described above, it has been found according to the invention that polyester carbonate prepolymers improve the incorporation of oligoester groups into polycarbonates. The result is the above-mentioned single-phase system. In addition to the compatibilization effect, the polyester carbonate prepolymer can also be simultaneously connected to the polycarbonate by chemical reactions. The preferred definitions in the chemical structures are given below. These are preferably each independently of one another or simultaneously applicable to the method for preparing a polyester carbonate prepolymer according to the invention, the polyester carbonate prepolymer according to the invention, the method for preparing a polyester carbonate blend according to the invention, the polyester carbonate blend and / or the use of the polyester carbonate prepolymer according to the invention. It will be clear to those skilled in the art that some chemical formulae are related (e.g. formula (I) and formula (Ia)) or can be derived from one another.

[0188] According to the present invention, preferably R1 in formula (I) and / or (Ia) is hydrogen. Also preferably Y in formula (II) is a structure of formula (III). In addition, preferably R1 in formula (I) and / or (Ia) is hydrogen, and Y in formula (II) is a structure of formula (III).

[0189] It is also preferred that R6 and R7 in formula (III) are each independently hydrogen or C1-C 12 -alkyl, more preferably hydrogen or C1-C8-alkyl, most preferably hydrogen or methyl. This is especially applicable to the case where R1 in formula (I) and / or (Ia) is hydrogen and Y in formula (II) is a structure of formula (III).

[0190] It is also preferred that X in formula (III) is isopropylidene. This is particularly applicable when R1 in formula (I) and / or (Ia) is hydrogen, Y in formula (II) is a structure of formula (III), and R6 and R7 in formula (III) are each independently hydrogen or C1-C 12 -alkyl, more preferably hydrogen or C1-C8-alkyl, most preferably hydrogen or methyl.

[0191] Particularly preferably, Y is introduced into the carbonate group (B) via a diphenol selected from the group consisting of 4′-dihydroxybiphenyl, 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.

[0192] The polyester carbonate blend of the present invention can be processed into all kinds of molded articles by itself. It can also be processed into thermoplastic molding materials together with other thermoplastics and / or polymer additives, which are then formed into molded articles. Molded articles are another theme of the present invention. The polymer additive is preferably selected from flame retardants, anti-drip agents, flame retardant synergists, smoke suppressants, lubricants and mold release agents, nucleating agents, antistatic agents, conductive additives, stabilizers (e.g., hydrolysis and heat aging stabilizers and transesterification inhibitors), flow promoters, phase compatibilizers, dyes and pigments, impact modifiers, and fillers and reinforcing agents.

[0193] Mouldings comprising the polyester carbonate blends according to the invention can be produced, for example, by injection moulding, extrusion and blow moulding processes.Another form of processing is the production of mouldings from previously produced sheets or films by deep drawing.

[0194] Brief description of the drawings:

[0195] Figure 1 :Comparative Example 2 at different reaction times 13 C-NMR spectrum partial

[0196] Figure 2 : Commercial products containing isophthalic acid / terephthalic acid-resorcinol ester blocks and BPA prepared by the phase interface method 13 C-NMR spectrum partial

[0197] Figure 3 : Example 1 of the present invention at different reaction times 13 C-NMR spectrum partial

[0198] Figure 4 : Schematic diagram of the experimental device of Example 5 of the present invention

[0199] Explanation of reference numerals:

[0200] 1Twin screw extruder

[0201] 2 Stirring tank

[0202] 3.1 Gear pump

[0203] 3.2 Gear Pump

[0204] 4. Static mixer

[0205] 5. Vacuum Pump

[0206] 6. Vacuum pump

[0207] 7. Condenser

[0208] 8 Condenser

[0209] 9. Water Bath

[0210] 10Strip pelletizing machine

[0211] a to k extruder housing

[0212] Figure 5 : Schematic diagram of the experimental device of Examples 6 and 7 of the present invention

[0213] Explanation of reference numerals:

[0214] 1Twin screw extruder

[0215] 2Differential weighing scale

[0216] 5. Vacuum Pump

[0217] 6. Vacuum pump

[0218] 7. Condenser

[0219] 8 Condenser

[0220] 9. Water Bath

[0221] 10Strip pelletizing machine

[0222] a to k extruder housing Example

[0223] Materials used:

[0224] Terephthalic acid: used for synthesis, CAS100-21-0, Bernd Kraft Duisburg

[0225] Isophthalic acid: 99%, CAS121-91-5, Sigma-Aldrich

[0226] Resorcinol: 99%, CAS108-46-3, ABCR

[0227] Diphenyl carbonate: 99.5%, CAS102-09-0; Acros Organics, Geel, Belgium, referred to as DPC

[0228] 4-Dimethylaminopyridine: ≥98.0%; pure; CAS1122-58-3; Sigma-Aldrich, München, Germany, referred to as DMAP

[0229] Tetrabutylphosphonium acetate (TBPAc): CAS-34430-94-9, prepared according to Angewandte Chemie, International Edition, Vol. 48, No. 40, 7398-7401; 2009

[0230] Sodium benzoate: ≥99%, CAS 532-32-1, Sigma-Aldrich

[0231] 3,4-Epoxycyclohexylcarboxylic acid (3',4'-epoxycyclohexane) methyl ester; CAS: 2386-87-0; Sigma-Aldrich, München, Germany

[0232] ADK Stab PEP 36: 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane; CAS 80693-00-1; ADEKA Europe GmbH 40212 Düsseldorf, Germany

[0233] Preparation of oligoester 1:

[0234] 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, 109.79 g (0.5125 mol) of diphenyl carbonate, 0.036 g of DMAP (4-dimethylaminopyridine; 200 ppm based on the raw material) and 0.054 g of tetrabutylphosphonium acetate (300 ppm) were pre-charged in a flask with a short path evaporator.

[0235] By evacuating and purging with nitrogen four times, oxygen in the mixture is removed. The mixture is melted and heated to 200°C while stirring at standard pressure. A suspension is formed because terephthalic acid is not initially dissolved in the melt. The reaction mixture is stirred at this temperature for about 3 hours. This releases carbon dioxide. Gradually heat to 240°C. Distill off phenol. The mixture is stirred at 240°C for about 1 hour. Finally, the mixture is stirred at 260°C for another half an hour. After the gas release ends, the reaction mixture is cooled to 210°C and the pressure is reduced. The pressure is gradually reduced to 60 mbar in 45 minutes. The temperature is raised to 230°C and stirred at this temperature for half an hour. The temperature is then raised to 245°C. The reaction mixture is continued to be stirred for 0.5 hours, and then the pressure is reduced to the minimum technically feasible limit (about 1 mbar). A light brown melt is thus produced. The analytical data are summarized in Table 1.

[0236] Preparation of oligoester 2:

[0237] The synthesis of oligoesters is in principle the same as that of oligoester 1.

[0238] Different from this, 62.31 g (0.375 mol) of terephthalic acid, 62.31 g (0.375 mol) of isophthalic acid, 86.70 g (0.7875 mol) of resorcinol, 329.37 g (1.5375 mol) of diphenyl carbonate, 0.216 g of DMAP (4-dimethylaminopyridine; 400 ppm based on the raw material) and 0.162 g of tetrabutylphosphonium acetate (300 ppm) were pre-charged in a flask with a short path evaporator.

[0239] The maximum temperature was 245°C bath temperature, replacing the 260°C stage with the same hold time.

[0240] The rest of the experiments were carried out similarly to the preparation of oligoester 1.

[0241] Preparation of oligoester 3:

[0242] The synthesis of oligoester 3 is in principle the same as that of oligoester 1.

[0243] Different from this, 62.31 g (0.375 mol) of terephthalic acid, 62.31 g (0.375 mol) of isophthalic acid, 107.37 g (0.975 mol) of resorcinol, 369.53 g (1.725 mol) of diphenyl carbonate, 0.24 g of DMAP (4-dimethylaminopyridine; 400 ppm based on the raw material) and 0.18 g of tetrabutylphosphonium acetate (300 ppm) were pre-charged in a flask with a short path evaporator.

[0244] The maximum temperature was 245°C bath temperature, replacing the 260°C stage with the same hold time.

[0245] The rest of the experiments were carried out similarly to the preparation of oligoester 1.

[0246] Table 1

[0247]

[0248] Oligocarbonate: The starting material for the preparation of polyester carbonate is a linear bisphenol A oligocarbonate containing phenyl and phenolic OH end groups and a relative solution viscosity of 1.17. The oligocarbonate does not contain any additives such as UV stabilizers, mold release agents or heat stabilizers. The oligocarbonate is prepared by the melt transesterification process described in WO02085967A1 and is taken off immediately at the outlet of the first horizontal reactor. The phenolic end group content of the oligocarbonate is 0.16% by weight.

[0249] Polycarbonate: Linear bisphenol A polycarbonate with phenyl end groups, MVR according to ISO 1133 of 13 g / 20 min.

[0250] Analytical methods:

[0251] Solution viscosity:

[0252] Determination of solution viscosity: The relative solution viscosity (η rel; also called eta rel) was measured in dichloromethane at a concentration of 5 g / l at 25°C using an Ubbelohde viscometer.

[0253] GPC:

[0254] The molecular weight is determined by gel permeation chromatography using dichloromethane as eluent. The standard used is BPA polycarbonate. The signal of the refractive index detector (RID) is used. The corresponding method is defined under the number 2301-0257502-09D of Currenta GmbH & Co. OHG, which can be obtained from Currenta at any time.

[0255] Determination of phenol OH end group content:

[0256] By infrared spectroscopy: Polyester carbonates dissolved in dichloromethane (2 g / 50 ml; 1 mm quartz cuvette) were analyzed in a Nicoleti S10 FT infrared spectrometer from Thermo Fisher Scientific. The wavelength 3583 cm was evaluated. -1 The phenolic OH end group content can be determined by the band at 1H-NMR spectroscopy: The measurement is carried out in dichloromethane with tetramethylsiloxane as internal standard. The OH group content is expressed in % by weight relative to the oligomer. For evaluation, the signal of the OH group is integrated and expressed according to the signal of the oligomer. Typically, the resonance of the OH group of the oligomer is at 5.3-5.6 ppm. (However, the person skilled in the art knows that the OH signal in NMR may shift depending on conditions such as the water content in the solvent.)

[0257] 13 C-NMR spectroscopy:

[0258] pass 13 C-NMR spectroscopy detects the bonding of isophthalic acid and / or terephthalic acid units to bisphenol A (see formula (VIIx)). Hereinafter, this is also referred to as IPA / TPA-BPA esters. Likewise, bonding of isophthalic acid and / or terephthalic acid units to resorcinol (see formula (Iax)) is detected. Hereinafter, this is also referred to as IPA-TPA-resorcinol esters.

[0259] The shift of the carbonyl carbon atom of isophthalic acid and / or terephthalic acid bonded to bisphenol A is at 164-165 ppm, while the signal of isophthalic acid and / or resorcinol terephthalate is at about 163-164 ppm.

[0260] The measurements were performed using a Bruker Avance III HD 600 MHz NMR spectrometer. The measurements were performed in CDCl3 with tetramethylsilane as the standard. The ratios of the different groups were determined by integration of the corresponding signals (area ratio to each other).

[0261] The glass transition temperature (Tg) was determined by differential scanning calorimetry (DSC) in accordance with DIN EN ISO 11357-1:2009-10 and ISO 11357-2:2013-05 under nitrogen at a heating rate of 10 K / min, the glass transition temperature (Tg) being measured as the inflection point in the second heating run.

[0262] Preparation of model ester compounds from BPA and terephthalic acid / isophthalic acid

[0263] 21.9 mmol BPA and a total of 21.9 mmol diphenyl esters formed from terephthalic acid and isophthalic acid were pre-loaded in a multi-necked round-bottom flask. 2.4 mg tetrabutylphosphonium acetate was added, which was equivalent to 0.02% of the total mass. The oxygen in the flask contents was removed by evacuating and inerting with nitrogen four times. The mixture was heated to 200 ° C while stirring continuously. Condensate was continuously formed. With the formation of phenol, the initially turbid liquid mixture became increasingly clear. An orange color was formed, which gradually deepened as the temperature increased to 230 ° C. About 80 minutes after the start of the reaction, the pressure was reduced to 10 to 100 mbar to remove phenol. A uniform orange-brown product was taken out.

[0264] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); IPA / TPA-BPA ester carbon atoms

[0265]

[0266] This substance was prepared in order to clearly identify the signals characteristic of the ester carbon atoms of the esters formed from BPA with terephthalic acid or isophthalic acid. It could be shown that the corresponding signals were located at 164.2 to 164.5 ppm.

[0267] Comparative Example 1

[0268] 8 g of oligoester 1 and 32 g of the above oligocarbonate were pre-charged into a multi-necked flask.

[0269] The contents of the flask are freed of oxygen by evacuating and inerting four times with nitrogen. The mixture is immersed in a metal bath at a temperature of 300°C. If possible, the melt is homogenized by means of a stirrer within 15 minutes. Subsequently, the stirrer speed is adjusted to 280-400 rpm and the pressure is rapidly reduced to the lowest technically feasible level, which must at least reach <3 mbar.

[0270] During the experiment, the melt viscosity increased continuously, and the condensate was removed continuously. After 10 minutes, the heating bath temperature was increased to 320° C. under the conditions described. After a further 10 minutes of heating, the heating bath temperature was increased to 335° C. under the conditions described. After 10 minutes, a highly viscous, transparent, green to orange product was taken out. 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); high intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); low intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 3.8:1)

[0271]

[0272] Comparative Example 1 shows that under the chosen reaction conditions the transesterification reaction in the direction of the IPA / TPA-BPA ester surprisingly proceeds almost completely. 13 This was confirmed by the high intensity of the corresponding signals in the C-NMR spectrum. Only a small amount of IPA / TPA-resorcinol esters remained.

[0273] Comparative Example 2

[0274] Weighing of reactants: 4 g of oligoester 1 and 36 g of polycarbonate were pre-loaded in a multi-necked flask. The operation was the same as that of Comparative Example 1.

[0275] Sample obtained directly after melting: turbid melt

[0276] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); very low intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); high intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 1:13)

[0277] Sample after 10 minutes: turbid melt

[0278] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); very low intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); high intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 1:10)

[0279] Sample after 20 minutes (after the temperature rises from 320 to 335°C): transparent melt

[0280] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); high intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); low intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 6:1)

[0281] Sample after 30 minutes: transparent melt

[0282] 13 C-NMR (xy MHz): 164.2-164.5 ppm (m, 1C); high intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); very low intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 10:1)

[0283] The samples after 0 minutes (directly after melting) and after 10 minutes showed that almost no transesterification reaction had occurred. The turbid melt also showed that the aromatic oligoester and the aromatic polycarbonate could not be mixed to form a clear mixture, ie a phase mixture of two separate polymer phases was established.

[0284] In contrast, the samples after 20 and 30 minutes were almost completely transesterified. In this case, the sample melt was transparent; this indicates a homogeneous polymer phase.

[0285] In comparative example 1, an oligomeric polycarbonate with a relatively high content of OH end groups was used. The reactivity of this product is therefore higher than that of the high molecular weight polycarbonate (with a lower content of phenolic OH groups) in comparative example 2. It is therefore all the more surprising that in this case, too, transesterification occurs almost completely. It would seem impossible to prepare homogeneous copolymers at low temperatures, since the two polymer phases coexist here without any reaction occurring. In contrast, at higher temperatures, transesterification occurs completely without any significant presence of IPA-TPA-resorcinol esters.

[0286] Different sample times 13 C-NMR spectra Figure 1 shown.

[0287] Comparative Example 3

[0288] Weighing of reactants: 4 g of oligoester 1 and 36 g of oligocarbonate were pre-loaded in a multi-necked flask.

[0289] The contents of the flask are freed of oxygen by evacuating and inerting four times with nitrogen. The mixture is immersed in a metal bath at a temperature of 300°C. If possible, the melt is homogenized by means of a stirrer within 15 minutes. Subsequently, the stirrer speed is adjusted to 280-400 rpm and the pressure is rapidly reduced to the lowest technically feasible level, which must at least reach <3 mbar.

[0290] Subsequently, a clear increase in melt viscosity and slight separation of the condensate were observed.

[0291] After 30 minutes, a highly viscous, transparent, green to orange product was removed.

[0292] Sample after 5 minutes:

[0293] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); medium intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); medium-high intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 1:1.7)

[0294] Sample after 15 minutes:

[0295] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); high intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); medium-low intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 1.7:1)

[0296] 30 minute sample:

[0297] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); high intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); low intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 3.8:1)

[0298] In this comparative example, it was examined whether the desired product containing a large amount of IPA-TPA-resorcinol ester could be prepared by lowering the temperature. However, it was found that after 5 minutes, the proportion of BPA ester was already significant, which increased further in the further course of the reaction. Therefore, it is questionable whether the desired product can be prepared by targeted temperature control.

[0299] Embodiment 1 of the present invention

[0300] Weighing of reactants: 8 g of oligoester 2 and 2 g of oligocarbonate were pre-loaded in a multi-necked flask.

[0301] The contents of the flask were freed of oxygen by evacuating and inerting four times with nitrogen. The mixture was immersed in a metal bath at a temperature of 310°C. If possible, the melt was homogenized as quickly as possible with a stirrer within 15 minutes. Subsequently, the stirrer speed was adjusted to 280-400 rpm and the pressure was rapidly reduced to the minimum technically feasible, which must at least reach <3 mbar. Subsequently, a clear increase in the melt viscosity and a slight separation of the condensate were observed.

[0302] After 30 minutes, a highly viscous, clear, green to orange product was removed (intermediate samples were removed after 5 and 15 minutes).

[0303] Sample after 5 minutes:

[0304] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); low intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); high intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 1:3.5)

[0305] Compared with the 5-minute sample, the signal intensity of the 15-minute sample and the 30-minute sample showed almost no change.

[0306] This indicates that a large amount of IPA-TPA-resorcinol ester can be obtained in this case. During the reaction, the amount of resorcinol ester does not change significantly.

[0307] Different sample times 13 C-NMR spectra Figure 2 shown.

[0308] Embodiment 2 of the present invention

[0309] Weighing of reactants: 8 g of oligoester 3 and 2 g of oligocarbonate were pre-loaded in a multi-necked flask. The operation was the same as that of "Example 1 of the present invention".

[0310] Sample after 5 minutes:

[0311] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); low intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); high intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 1:11.5)

[0312] Compared with the 5-minute sample, the signal intensity of the 15-minute sample and the 30-minute sample showed almost no change.

[0313] This indicates that a large amount of IPA-TPA-resorcinol ester can also be obtained in this case. During the reaction, the amount of resorcinol ester does not change significantly.

[0314] Embodiment 3 of the present invention

[0315] Weighing of reactants: 1.875 g of the product of the experiment described in Example 1 of the present invention and 13.125 g of polycarbonate were pre-loaded in a multi-necked flask so that the mass proportion of oligoesters reached 10%. 7.5 mg of 3,4-epoxycyclohexylcarboxylic acid (3',4'-epoxycyclohexane) methyl ester and 15 mg of ADK Stab PEP-36 were added. Cover with nitrogen for 10 minutes to remove oxygen from the contents of the flask. The mixture was immersed in a metal bath at 300°C. If possible, homogenize the melt with a stirrer within 15 minutes as quickly as possible. Subsequently, a sample was taken out (0 minutes). Now adjust the stirrer speed to 280-400 rpm and quickly reduce the pressure to the minimum technically feasible, which must reach at least <3 mbar. Subsequently, a significant increase in melt viscosity and a slight separation of condensate were observed.

[0316] After 30 minutes, a highly viscous, clear, green to orange product was removed (intermediate samples were removed after 5 and 15 minutes).

[0317] Sample after 0 minutes (after melting):

[0318] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); low intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); high intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 1:3)

[0319] Sample after 5 minutes:

[0320] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); low-medium intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); high intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 1:2)

[0321] Sample after 15 minutes:

[0322] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); medium intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); medium-high intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 1:1.4)

[0323] Sample after 30 minutes:

[0324] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); medium intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); medium intensity; IPA-TPA-resorcinol ester carbon atoms (ratio is about 1:1). The eta rel of this sample is 1.309.

[0325] 13 The C-NMR spectrum shows that only after a reaction time of 30 minutes, the ratio of IPA / TPA-BPA esters is approximately the same as the ratio of IPA-TPA-resorcinol esters. Until a reaction time of 15 minutes, the ratio of IPA-TPA-resorcinol esters is significantly higher. Compared with the comparative example, this example surprisingly shows that the melt undergoes transesterification relatively slowly. Surprisingly, even with a high ratio of BPA polycarbonate, only a small proportion is transesterified to IPA / TPA-BPA esters.

[0326] Embodiment 4 of the present invention

[0327] Weighing of reactants: 1.875 g of the product of the experiment described in Example 2 of the present invention and 13.125 g of polycarbonate were pre-loaded in a multi-necked flask so that the mass ratio of the oligoester reached 10%. 7.5 mg of 3,4-epoxycyclohexylcarboxylic acid (3',4'-epoxycyclohexane) methyl ester and 15 mg of ADK Stab PEP-36 were added. The operation method was the same as that of "Example 3 of the present invention".

[0328] Sample after 0 minutes (after melting):

[0329] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); low intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); high intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 1:4.3)

[0330] Sample after 5 minutes:

[0331] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); low intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); high intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 1:4)

[0332] Sample after 15 minutes:

[0333] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); low intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); high intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 1:2.5)

[0334] Sample after 30 minutes:

[0335] 13 C-NMR (600 MHz): 164.2-164.5 ppm (m, 1C); low-medium intensity; IPA / TPA-BPA ester carbon atoms; 163.6-163.8 ppm (m, 1C); medium intensity; IPA-TPA-resorcinol ester carbon atoms (ratio of about 1:2.1)

[0336] In this example, the tendency for transesterification is still lower. Even after 30 minutes, the proportion of IPA-TPA-resorcinol ester is still surprisingly greater.

[0337] Embodiment 5 of the present invention

[0338] For Example 5 of the present invention, use Figure 4 Schematic diagram of the experimental setup.

[0339] 830.7g (5.0mol) of terephthalic acid, 830.7g (5.0mol) of isophthalic acid, 1156.05g of resorcinol and 4284.4g (20.0mol) of diphenyl carbonate were pre-loaded in a stirred tank (2). In addition, 2.84g of dimethylaminopyridine and 2.13g of tetrabutylphosphonium acetate were added to the reaction mixture. The oxygen in the kettle was removed by repeatedly evacuating and inerting with nitrogen. The reaction mixture was melted at standard pressure, and the liquid reaction mixture was transported back to the stirred tank (2) by a gear pump (3.1) through a static mixer (4). The temperature of the kettle was gradually increased to 245°C. This released carbon dioxide and removed it from the reaction vessel. After the carbon dioxide emission ended and the reaction mixture became clear, the kettle was cooled to 210°C and the pressure was gradually reduced to 60mbar within 30 minutes. Phenol can be continuously removed from the reaction mixture in this way. The holding stage lasted for 30 minutes. The temperature was then raised to 230°C and kept constant for a further 30 minutes. The temperature was then raised to 245°C and kept constant for 30 minutes. The highest possible vacuum (<1 mbar) was then applied and the conditions were maintained for a further 30 minutes.

[0340] The reactor (2) is cooled and 600.6 g of oligocarbonate are added to the reaction mixture. The mixture is melted at 250° C. and the pressure is gradually reduced to <1 mbar. The melt is stirred at 17.5 rpm with a spiral stirrer and conveyed through a loop pipe with a static mixer (4) using a gear pump (3.1). The melt circulates in this way for 75 minutes. The polymer melt is then continuously conveyed to a twin-screw extruder (1) (model: ZSE 27MAXX, which has 11 shells, from Leistritz Extrudestechnik GmbH, Nürnberg) via a second gear pump (3.2) at a throughput of 1.2 kg / h. The extruder housing is located at Figure 4Indicated by letters "a" to "k". The extruder is operated at 100 rpm with a shell temperature of 310°C. The melt is fed into the fourth shell (d) of the extruder. Reverse devolatilization is carried out through the first shell (a) of the extruder (a) at an absolute pressure of 25 mbar. A vacuum of 25 absolute mbar is applied to the fifth shell of the extruder (e), and a vacuum of 3-5 absolute mbar is applied to shells (g), (i) and (j). The polymer melt is extruded at a melt temperature of 311°C, introduced into a water bath (9) and pelletized using a strand pelletizer (10). The Mn of the polymer sample is 3750 g / mol and the Mw is 8300 g / mol (RID).

[0341] Embodiment 6 of the present invention

[0342] The experimental device of Example 6 of the present invention is as follows Figure 5 shown.

[0343] 468.75 g of the granulated product from inventive example 5, 3281.25 g of polycarbonate and 1.875 g of (cyclohexyloxy)methyl 3,4-epoxycyclohexylcarboxylate and 3.750 g of ADK Stab PEP 36 were mixed in a drum ring mixer for 30 minutes.

[0344] The mixture was continuously fed into the feed housing (a) of a twin-screw extruder (1) (model: ZSE 27MAXX, with 11 housings, from Leistritz Extrudestechnik GmbH, Nürnberg) at a throughput of 2 kg / h via a differential metering scale (2) and extruded at 150 rpm. Figure 5 The mixture was extruded at a melt temperature of 329° C. at a shell temperature of 160° C. in shell (b), 240° C. in shell (c), 300° C. in shell (d), 320° C. in shells (f) to (k), introduced into a water bath (9) and pelletized with a strand pelletizer (10). The extruders had devolatilization zones at shells (e), (g), (i) and (j). They were operated at standard pressure.

[0345] The product has the following analytical data: transparent granules, etarel: 1.225, Tg: 143°C, 13 The C spectrum had mainly IPA-TPA-resorcinol ester (ratio about 1:2.6).

[0346] Embodiment 7 of the present invention

[0347] The experimental device of Example 7 of the present invention is as follows Figure 5 shown.

[0348] The mixture of Example 6 according to the invention was introduced continuously into the inlet housing (a) of a twin-screw extruder (1) (model: ZSE 27MAXX, with 11 housings, from Leistritz Extrudestechnik GmbH, Nürnberg) at a throughput of 1.4 kg / h via a differential metering scale (2) and extruded at 100 rpm. Figure 5 The mixture was extruded at a melt temperature of 328° C. at a shell temperature of 160° C. in housing (b), 240° C. in housing (c), 300° C. in housing (d), 320° C. in housings (f) to (k), introduced into a water bath (9) and pelletized using a strand pelletizer (10). A vacuum of 32 mbar absolute was applied to housing (e) of the extruder, and a vacuum of <1 mbar absolute was applied to housings (g), (i) and (j).

[0349] The product has the following analytical data: transparent particles, etarel: 1.230, Tg: 145°C, 13 The C-spectrum had mainly IPA-TPA-resorcinol ester (ratio about 1:2.6).

[0350] Extrusion experiments have shown that the desired polyester carbonates can be prepared by the process of the invention which still contain a high degree of the desired resorcinol ester bonds.

Claims

1. A method for preparing a polyester carbonate prepolymer, comprising the following steps: (a) providing an oligoester comprising a structure of formula (I) wherein R1 is each independently a hydrogen atom, a halogen or an alkyl group having 1 to 4 carbon atoms, and n is at least 4, (b) providing oligocarbonates and / or polycarbonates, and (c) reacting 65 to 95% by weight of the oligoester from step (a) with 35 to 5% by weight of the oligocarbonate and / or polycarbonate from step (b) by condensation reaction in the molten state to obtain a polyester carbonate prepolymer, wherein the % by weight are based on the total weight of the oligoester from step (a) and the oligocarbonate and / or polycarbonate from step (b).

2. The method according to claim 1, characterized in that: The number average molecular weight Mn of the oligoester from step (a) is from 500 g / mol to 8000 g / mol, preferably from 600 g / mol to 5000 g / mol, more preferably from 700 g / mol to 3000 g / mol.

3. The method according to any one of claims 1 or 2, characterized in that The oligomeric polycarbonate from step (b) has a relative solution viscosity of from 1.08 to 1.22, preferably from 1.11 to 1.22, more preferably from 1.13 to 1.

20.

4. The method according to any one of claims 1 to 3, characterized in that Step (c) is carried out at a reduced pressure relative to ambient pressure.

5. A polyester carbonate prepolymer comprising (A) Ester group of formula (Ia) wherein R1 are each 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 at which the ester group is incorporated into the polyester carbonate blend, (B) Carbonate group of formula (II) wherein Y is independently a structure of formula (III), (IV), (V) or (VI), wherein in R6 and R7 are each independently hydrogen, C1-C 18 Alkyl, C1-C 18 alkoxy, halogen or in each case optionally substituted aryl or aralkyl, and X is a single bond, –CO–, –O–, –S–, C1- to C6-alkylene, C2- to C5-alkylidene, C6- to C 10 -cycloalkylidene, or a C6- to C6- 12 -arylene group, in, In these formulae (IV) to (VI), R 3 is in each case C1-C4-alkyl, aralkyl or aryl, preferably methyl or phenyl, most preferably methyl, and "*" in each case indicates the position at which the carbonate group in formula (III), (IV), (V) or (VI) is bonded to the carbonate group in formula (II), m represents the average number of repeating units, "*" each represents the position where a carbonate group is incorporated into the polyester carbonate blend, wherein at least a portion of the ester groups (A) are directly linked to at least a portion of the carbonate groups (B) via formula (VII), wherein wherein Y has the above definition for (B), and (A) represents a connection to an ester group (A), and (B) represents a connection to a carbonate group (B), Characterized in that the polyester carbonate prepolymer contains a mole % of carbon atoms indicated by the arrow in formula (Ia) that is greater than the mole % of carbon atoms indicated by the arrow in formula (VII); wherein R1, n and "*" have the above definitions, and wherein (A), Y and (B) have the above definitions.

6. A method for preparing a polyester carbonate blend comprising the steps of: (i) providing a polyester carbonate prepolymer according to claim 5 or a polyester carbonate prepolymer prepared by the process according to any one of claims 1 to 4, (ii) providing a polycarbonate having a weight average molecular weight Mw of 24,000 to 40,000 g / mol, the weight average molecular weight being determined by gel permeation chromatography with calibration against bisphenol A polycarbonate standards using dichloromethane as eluent, (iii) converting the polyester carbonate prepolymer from step (i) and the polycarbonate from step (ii) into a molten state and mixing 5 to 25 wt. % of the polyester carbonate prepolymer with 95 to 75 wt. % of the polycarbonate in the molten state to obtain a polyester carbonate blend, wherein the wt. % is based on the total weight of the polyester carbonate prepolymer from step (i) and the polycarbonate from step (ii).

7. The method according to claim 6, characterized in that In process step (iii) at least one stabilizer is present.

8. The method according to any one of claims 6 or 7, characterized in that Process step (iii) is carried out at a reduced pressure relative to the ambient pressure.

9. A polyester carbonate blend comprising (A) Ester group of formula (Ia) wherein R1 are each 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 at which the ester group is incorporated into the polyester carbonate blend, (B) Carbonate group of formula (II) wherein Y is independently a structure of formula (III), (IV), (V) or (VI), wherein in R6 and R7 are each independently hydrogen, C1-C 18 -alkyl, C1-C 18 - alkoxy, halogen or in each case optionally substituted aryl or aralkyl, and X is a single bond, –CO–, –O–, –S–, C1- to C6-alkylene, C2- to C5-alkylidene, C6- to C 10 -cycloalkylidene, or a C6- to C6- 12 -arylene group, in, In these formulae (IV) to (VI), R 3 is in each case C1-C4-alkyl, aralkyl or aryl, preferably methyl or phenyl, most preferably methyl, and "*" in each case indicates the position at which the carbonate group in formula (III), (IV), (V) or (VI) is bonded to the carbonate group in formula (II), m represents the average number of repeating units, "*" each represents the position where a carbonate group is incorporated into the polyester carbonate blend, wherein at least a portion of the ester groups (A) are directly linked to at least a portion of the carbonate groups (B) via formula (VII), wherein wherein Y has the above definition for (B), and (A) represents a connection to an ester group (A), and (B) represents a connection to a carbonate group (B), wherein the polyester carbonate blend has a relative solution viscosity of at least 1.21 and at most 1.38, Characterized in that the polyester carbonate blend contains a mole % of carbon atoms indicated by the arrow in formula (Ia) that is greater than the mole % of carbon atoms indicated by the arrow in formula (VII); wherein R1, n and "*" have the above definitions, and wherein (A), Y and (B) have the above definitions.

10. The polyester carbonate blend according to claim 9, characterized in that The polyester carbonate blend has a phenolic OH group content of greater than 0 ppm to less than or equal to 500 ppm.

11. Use of the polyester carbonate prepolymer according to claim 5 or the polyester carbonate prepolymer prepared by the method according to any one of claims 1 to 4 for compatibilizing oligoesters containing the structure of formula (I) with polycarbonate wherein R1 is each independently a hydrogen atom, a halogen or an alkyl group having 1 to 4 carbon atoms, and n is at least 4.

12. A method for preparing a polyester carbonate prepolymer according to any one of claims 1 to 4, a polyester carbonate prepolymer according to claim 5, a method for preparing a polyester carbonate blend according to any one of claims 6 to 8, a polyester carbonate blend according to any one of claims 9 or 10 or the use according to claim 11, characterized in that R1 in formula (I) or formula (Ia) is hydrogen.

13. A method for preparing a polyester carbonate blend according to any one of claims 6 to 8 or 12 or a polyester carbonate blend according to any one of claims 9 to 10 or 12, characterized in that Y in formula (II) represents the structure of formula (III).

14. The method for preparing a polyester carbonate blend according to any one of claims 6 to 8 or 12 to 13 or the polyester carbonate blend according to any one of claims 9 to 10 or 12 to 13, characterized in that R6 and R7 in formula (III) are each independently hydrogen or C1-C 12 -alkyl, more preferably hydrogen or C1-C8-alkyl, most preferably hydrogen or methyl.

15. A molded article comprising the polyester carbonate blend according to any one of claims 9 to 10 or 12 to 14.

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