Polycarbonates having carboxy end groups and methods for producing said polycarbonates

Abstract

The present invention relates to aromatic polycarbonates containing A) structural units derived from hydroxybenzoic acid and having a free COOH function present as end groups, and B) structural units derived from hydroxybenzoic acid, component B) being selected from B1) structural units derived from hydroxybenzoic acid and having an esterified COOH function present as end group, and B2) at least one representative of structural units derived from hydroxybenzoic acid which are incorporated into the polymer chain through an ester group or an anhydride group, and the molar ratio of the amount of component A to the amount of component B is in the range from 1.3 to 50, as well as copolymers, and thermoplastic molding compounds and moldings containing such polycarbonates or copolymers, a process for producing said polycarbonates, and a process for producing said copolymers and the use of said polycarbonates for this purpose.

Description

[Technical field]

[0001] The present invention relates to aromatic polycarbonates having carboxy end groups, a process for making the aromatic polycarbonates, the use of the aromatic polycarbonates to make copolymers, a process for making the copolymers, and molding compounds and molded articles containing the copolymers. [Background technology]

[0002] Polycarbonates have been used for many years to produce transparent or translucent (transilluminable) molded articles. The automotive, architectural and electronics sectors have recently achieved applications with new lighting concepts and functional integration using transilluminable molding compounds.

[0003] However, for some applications, polycarbonate is inadequate with respect to important properties such as, for example, scratch resistance, stress crack resistance under the influence of chemicals, mechanical properties and processing properties (melt flowability). The development of polymer blends of polycarbonate with other thermoplastics is an approach often used to achieve a specific technical requirement profile by combining certain favorable properties of polycarbonate with those of the polymer blending partners, ideally synergistically. Polymer blends of polycarbonate (PC) and polymethylmethacrylate (PMMA) can show improvements over pure polycarbonate, for example, with respect to scratch resistance, stress crack resistance under the influence of chemicals and melt flowability. At the same time, the material ductility can be increased compared to polymethylmethacrylate.

[0004] However, the favorable combination of properties that can be achieved in such polymer blends often interferes with the transparency / light transmission of the molded articles produced therefrom.Polycarbonate and further thermoplastics present in polymer blends are generally incompletely mixed, and therefore form a two-phase morphology that includes a matrix phase of one polymer and domains of the other polymer distributed therein.Since the refractive indexes of the blending partners are typically different, light scattering occurs at many phase interfaces, and therefore the light transmission is generally significantly reduced compared to that of the pure blending components.Such blends of polycarbonate and polycarbonate-immiscible polymers are therefore generally opaque, i.e., cannot transmit light, or can transmit light only with inadequate light yield.

[0005] Phase interfaces may furthermore constitute mechanical weak points which may lead to material failure, especially under the influence of chemicals.

[0006] To achieve improved compatibility of polycarbonate with PC immiscible thermoplastic blending partners, such as PMMA, one option described in the literature is the in situ formation during reactive extrusion of block copolymers derived from polycarbonate and the polymeric blending partner, in this particular case PMMA. The chemical reaction of the two polymers at the phase interface of the biphasic molten mixture can be accelerated through the use of a catalyst.

[0007] Patent document 1 discloses a reactive compounding method for producing thermoplastic molding compounds using aromatic polycarbonates that do not contain reactive functional groups and further polymers that contain at least one type of functional group selected from ester, epoxy, hydroxy, carboxy and carboxylic anhydride groups, in which the catalysts used are special phosphonium salts. The application also discloses, in particular, the production of transparent thermoplastic PC / PMMA molding compounds in such a process.

[0008] US Patent No. 5,399,633 discloses transparent PC / PMMA blends containing 9.9% to 40% by weight of polycarbonate and 59.9% to 90% by weight of PMMA, which are produced from non-reactive functionalized polymer components in a reactive melt extrusion process using 0.0025% to 0.1% by weight of a tin catalyst.

[0009] US Pat. No. 5,399,433 discloses transparent PC / PMMA blends containing 80% to 95% by weight of a specifically specified branched polycarbonate having an end cap content of 45% to 80% and 4.9% to 20% by weight of PMMA, which are produced in melt extrusion by transesterification using 0.1% to 1.5% by weight of a catalyst, preferably selected from Zn, Sn and Ag compounds.

[0010] Molded parts made with blended compositions produced by these methods have an improvement in terms of light transmittance compared to molded parts made with PC / PMMA compositions produced by a purely physical mixing process, but generally still have inadequate light yields for many applications in terms of illumination transmission, and inadequate mechanical properties, especially insufficient material ductility.

[0011] In addition to the described use of catalysts, appropriate functionalization of polycarbonates can likewise favor the in situ formation of copolymers.

[0012] US Pat. No. 5,399,633 and US Pat. No. 5,499,663 describe the preparation of terminally carboxy-functionalized polycarbonates, in which phenols substituted with carboxylic acids or carboxylic acid derivatives, preferably t-butyl p-hydroxybenzoate, are incorporated at the end of PC as chain terminators in the polycarbonate-forming reaction. Also disclosed are methods for preparing block copolymers of epoxy-functionalized olefin polymers with such carboxy- or carboxylic acid derivative-functionalized polycarbonates by reaction in organic solution or during melt compounding, and the use of such copolymers for compatibilizing polymer blends of polycarbonate and polyolefins with the aim of reducing the tendency to delamination. These applications give no hint as to the suitability of polycarbonates functionalized in this way for the preparation of transparent PC / PMMA blends.

[0013] With regard to the latter approach, which concerns the reaction between a suitably functionalized polycarbonate and a polymeric compounding partner, the exact type of functionalization of the polycarbonate, i.e. the selection and concentration of suitable reactive groups, is of great importance, as is the efficient method of its manufacture. The molding compounds produced from the polycarbonate and the compounding partner should also be suitable for processing into thermoplastics to provide molded articles. In view of the prior art, there remains a need for improvement in these aspects. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] International Publication No. 2020 / 212229 [Patent Document 2] International Publication No. 2016 / 138246 [Patent Document 3] International Publication No. 2016 / 189494 [Patent Document 4] U.S. Patent No. 4,853,458 [Patent Document 5] U.S. Patent No. 4,959,411 Summary of the Invention [Problem to be solved by the invention]

[0015] It was therefore desirable to provide aromatic polycarbonates which are particularly suitable for producing block copolymers containing at least one polycarbonate block suitable as a compatibilizer, for example in polymer blends.

[0016] It was particularly desirable to provide aromatic polycarbonates that are particularly suitable for producing thermoplastic, light-transmitting molding compounds and molded articles, which contain polycarbonate and a vinyl polymer, preferably polymethyl methacrylate.

[0017] It would also be desirable to provide a process by which functionalized polycarbonates could be produced easily and at an advantageous ratio to undesirable by-products. [Means for solving the problem]

[0018] Surprisingly, an aromatic polycarbonate comprising A) a structural unit derived from hydroxybenzoic acid and having a free COOH functional group present as an end group; B) A structural unit derived from hydroxybenzoic acid, Component B) is B1) structural units derived from hydroxybenzoic acid and having an esterified COOH functional group present as a terminal group, and B2) structural units derived from hydroxybenzoic acid which are incorporated into the polymer chain via an ester group (=B2-a) or an anhydride group (=B2-b); A structural unit selected from at least one representative of Contains It has now been found that desirable properties are exhibited by aromatic polycarbonates in which the molar ratio of the amount of component A to the amount of component B is in the range of 1.3-50.

[0019] In a preferred embodiment, the polycarbonate further contains, as component C, structural units derived from monophenols (i.e. aromatic compounds having only one phenolic OH function) that do not contain a carboxy or carboxy derivative function as a terminal group.

[0020] It is further preferable that Component C is present in the polycarbonate according to the present invention in a molar ratio of 20 mol % to 90 mol %, particularly preferably 40 mol % to 85 mol %, more preferably 45 mol % to 80 mol %, and particularly preferably 50 mol % to 75 mol %, relative to the total molar ratios of Component A, Component B1, Component B2, and Component C, which is 100 mol %. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] In the context of the present application, the terms "carboxy" and "carboxyl" are used interchangeably and denote the COOH group.

[0022] The aromatic polycarbonates according to the invention are referred to hereinafter as aromatic polycarbonates containing (terminal) COOH end groups.

[0023] Similarly, it is surprising that these aromatic polycarbonates (i) as a chain terminator An ester of a hydroxybenzoic acid, preferably p-hydroxybenzoic acid, or a mixture of two or more esters of one or more structurally distinct hydroxybenzoic acids, more preferably having the general structural formula (1): [ka] (wherein R1 and R2 independently of one another represent hydrogen or an alkyl, aryl or alkylaryl radical having 1 to 10 carbon atoms, preferably hydrogen or an alkyl radical having 1 to 4 carbon atoms, particularly preferably hydrogen or a methyl radical, most preferably both represent a methyl radical, 2. The process for producing aromatic polycarbonates containing end groups derived from hydroxybenzoic acid esters by phosgenation in the presence of an ester of an ester of an alkyl group having 1 to 10 carbon atoms, an aryl group or an alkylaryl group, preferably hydrogen or an alkyl radical having 1 to 4 carbon atoms, particularly preferably hydrogen or a methyl radical, most preferably hydrogen, with an alcohol, in a phase interface process or in an organic solution of an aromatic diol, in the preparation according to process step (i), not exceeding at any time a temperature of 260°C, preferably a temperature of 240°C, more preferably a temperature of 230°C, most preferably a temperature of 200°C; (ii) subjecting the end groups derived from the hydroxybenzoic acid ester in the product of process step (i) to thermal end group pyrolysis to remove an alkene of general structural formula R3R4C=CR1R2, where R1, R2, R3, and R4 are as defined above, In process step (ii), the product from process step (i) is pyrolyzed by supplying thermal or mechanical energy at a temperature range of 230° C. to 265° C., preferably 230° C. to 260° C., particularly preferably 230° C. to 255° C., and the resulting alkenes are removed from the apparatus; A residence time in a temperature range of 230°C to 265°C, preferably 230°C to 260°C, particularly preferably 230°C to 255°C, is 15 seconds or more and 10 minutes or less, preferably 20 seconds or more and 5 minutes or less, particularly preferably 30 seconds or more and 2 minutes or less; It has been found that the compound can be produced by a method comprising the steps of:

[0024] The alcohol with which the hydroxybenzoic acid is esterified is preferably a tertiary alcohol, most preferably tert-butanol.

[0025] Surprisingly, it has been found that polycarbonates having the structural characteristics according to the invention, necessary for solving the technical problem, are not obtainable if the abovementioned temperature and residence time conditions are not observed.

[0026] In a preferred embodiment, process step (ii) is carried out in a compounding apparatus selected from the group comprising single-screw extruders, co-rotating or counter-rotating twin-screw extruders, planetary roller extruders, continuous or discontinuous internal kneaders and filmtruders, in which in process step (ii) the product from process step (i) is melted in these compounding apparatuses by supplying thermal or mechanical energy and pyrolyzed at a melting temperature in the temperature range of 230°C to 265°C, preferably 230°C to 260°C, particularly preferably 230°C to 255°C, the resulting alkenes being removed from the apparatus and the residence time in the temperature range of 230°C to 265°C, preferably 230°C to 260°C, particularly preferably 230°C to 255°C is ≥ 15 s and ≤ 10 min, preferably ≥ 20 s and ≤ 5 min, particularly preferably ≥ 30 s and ≤ 2 min. In this preferred embodiment, preferably, prior to use in process step (ii), the aromatic polycarbonate produced in process step (i) is (ia) after polymerization in the presence of esters of hydroxybenzoic acid in a phase interface process or by phosgenation in organic solutions of aromatic diols, (ib) isolated in a downstream work-up step, ie the solvent or solvent mixture used in process step (ia) is at least largely separated.

[0027] In both the polymerization process step (ia) and the post-treatment step (ib), the temperature does not exceed a temperature of 260°C at any time, preferably does not exceed a temperature of 240°C at any time, more preferably does not exceed a temperature of 230°C at any time, and most preferably does not exceed a temperature of 200°C at any time.

[0028] The work-up according to step (ib) is carried out in particular by spray drying or precipitation of the polycarbonate in a suitable solvent, for example isopropanol, methanol or water, followed by separation of the solvent phase, which can be carried out for example by filtration, settling followed by decantation, centrifugation or a combination of these processes, in each case followed by drying, which is preferably carried out in the temperature range from 60° C. to 120° C., particularly preferably with the application of negative pressure.

[0029] In an alternative, likewise preferred process, process step (ii) can also be carried out in the context of isolation of the polycarbonate from process step (i), i.e. for example, in the context of removal of the (residual) solvent. In this case, the solvent / solvent mixture, or after partial removal of the solvent / solvent mixture in process step (ib), the residual solvent or solvent mixture is removed in process step (ii) by supplying thermal or mechanical energy, optionally with application of negative pressure, in a temperature range of 230° C. to 265° C., preferably 230° C. to 260° C., particularly preferably 230° C. to 255° C., while at the same time the end groups from the hydroxybenzoic acid esters are thermally pyrolyzed and the resulting alkenes are likewise removed from the apparatus, with a residence time in the temperature range of 230° C. to 265° C., preferably 230° C. to 260° C., particularly preferably 230° C. to 255° C. of ≥15 s and ≤10 min, preferably ≥20 s and ≤5 min, particularly preferably ≥30 s and ≤2 min. Suitable process equipment for such a method according to the invention preferably includes those selected from the group consisting of degassing extruders, strand evaporators, film truders and foam evaporators.

[0030] Aromatic Polycarbonate The aromatic polycarbonate according to the present invention is A) structural units derived from hydroxybenzoic acid and having a free COOH function present as a terminal group (also called COOH or equivalently carboxy or carboxyl terminal group), B) A structural unit derived from hydroxybenzoic acid, wherein component B) is B1) structural units derived from hydroxybenzoic acid and having an esterified COOH functional group present as a terminal group, and B2) structural units derived from hydroxybenzoic acid which are incorporated into the polymer chain via an ester group (=B2-a) or an anhydride group (=B2-b); and a structural unit selected from at least one representative of Contains The molar ratio of the amounts of component A and component B is in the range of 1.3 to 50, preferably in the range of 1.5 to 25, particularly preferably in the range of 1.8 to 10, and most preferably in the range of 2.0 to 5.0.

[0031] In calculating the molar ratio of the amounts of component A and component B, the molar amount of component B used is the sum of the molar amounts of components B1, B2-a and B2-b.

[0032] The polycarbonates according to the invention preferably have an acid number of at least 0.3 mg potassium hydroxide (KOH) / g, more preferably at least 0.5 mg potassium hydroxide (KOH) / g, more preferably at least 1.0 mg KOH / g and most preferably at least 1.5 mg KOH / g, determined in each case at room temperature by potentiometric titration with ethanolic KOH solution in dichloromethane (DCM) / ethanol as solvent according to DIN EN ISO 2114, method A, version 2002-6.

[0033] The polycarbonates according to the invention preferably have an acid number in the range from 0.5 mg potassium hydroxide (KOH) / g to 10 mg potassium hydroxide (KOH) / g, more preferably from 1 mg KOH / g to 7 mg KOH / g, particularly preferably from 1.3 mg KOH / g to 5.0 mg KOH / g and most preferably from 1.5 mg KOH / g to 3.5 mg KOH / g, determined in each case at room temperature by potentiometric titration with ethanolic KOH solution in dichloromethane (DCM) / ethanol as solvent according to DIN EN ISO 2114, method A, version 2002-6.

[0034] To determine the acid number, the polymer to be studied was dissolved at a concentration of 10 g / L in 50 mL of dichloromethane at room temperature. 5 mL of ethanol was added to the sample solution before potentiometric titration with 0.1 N ethanolic KOH.

[0035] In a preferred embodiment, the polycarbonate is characterized in that the molar ratio of the amount of component B2 to the sum of the amounts of components A and B2 is less than 0.3, preferably less than 0.2. In calculating this molar ratio, the molar amount of component B2 used is the sum of the molar amounts of components B2-a and B2-b.

[0036] In a further preferred embodiment, the polycarbonate is characterized in that the molar ratio of the amount of component A to the sum of the amounts of components A and B1 is greater than 0.75, preferably greater than 0.9.

[0037] Benzoic acids contemplated include hydroxybenzoic acids having a carboxylic acid group para, meta, or ortho to the phenolic OH group. Hydroxybenzoic acids having a carboxylic acid group para to the phenolic OH group are preferred. These have a C1-C 10 It may be singly or multiply substituted with alkyl, aryl or alkylaryl radicals, preferably with C1-C4 alkyl radicals, particularly preferably with methyl, or alternatively with halogen or ester groups, for example preferably with methoxy.

[0038] The structural units derived from hydroxybenzoic acid are particularly preferably structural units derived from p-hydroxybenzoic acid which do not contain further substituents.

[0039] The structural units according to component B1 which are derived from hydroxybenzoic acid and have an esterified COOH function present as a terminal group are preferably esters of hydroxybenzoic acid (preferably p-hydroxybenzoic acid), more preferably esterified with an alcohol of the above-mentioned structural formula (1).

[0040] The alcohol is preferably a tertiary alcohol, most preferably tert-butanol.

[0041] The structures of component A, component B1 and component B2 are shown as examples in formula (2), formula (3), formula (4a) and formula (4b) for p-hydroxybenzoic acid, which is particularly preferred as hydroxybenzoic acid, where formula (2) represents component A, formula (3) represents component B1 (particularly preferred tert-butyl ester example), and formula (4a) and formula (4b) represent component B2. Formula (4a) shows a structural unit derived from hydroxybenzoic acid that is incorporated into the polymer chain through an ester group (component B2-a). Formula (4b) shows a structural unit derived from hydroxybenzoic acid that is incorporated into the polymer chain through an acid anhydride group (component B2-b).

[0042] In formula (2), formula (3), formula (4a) and formula (4b), m and n each represent the number of monomer units shown in parentheses. [ka] TIFF2024525481000003.tif94170

[0043] The molar ratios of component A to component B1 and the molar ratios of the two possible structures of component B2 and the corresponding molar ratios of these components in the context of the present invention are: 1The molar ratios are determined by H NMR spectroscopy. To this end, the polycarbonate is dissolved in deuterated chloroform at room temperature. The different structural units derived from hydroxybenzoic acid can be distinguished through the NMR signals of the aromatic protons that are ortho to the carboxy / derivatized carboxy functional group, and the molar amounts / ratios of the different structures can be quantified based on the integrated intensities of these signals. In the case of the particularly preferred p-hydroxybenzoic acid, the spin-spin coupling of the aromatic protons that are ortho to the carboxy / derivatized carboxy functional group and the aromatic protons that are meta means that doublets are taken into account in all cases. For all components A, B1 and B2, the corresponding NMR signals are each due to two protons, and therefore the ratio of the intensities of the corresponding NMR signals allows the corresponding molar ratios of the ratios of the different components in the polycarbonate to be directly derived.

[0044] In the special case of p-hydroxybenzoic acid which is particularly preferred, The protons in the structural unit derived from p-hydroxybenzoic acid described in component A resonate in the range of approximately 8.14 ppm, The protons in the structural unit derived from p-hydroxybenzoic acid described in component B1 in the case of the tert-butyl ester described in formula (2) resonate in the range of approximately 8.05 ppm, The protons in the structural units derived from p-hydroxybenzoic acid according to component B2-b (formula 4b), which are incorporated into the polymer chain through the acid anhydride group, resonate in the range of approximately 8.22 ppm. The protons in the structural units derived from p-hydroxybenzoic acid according to component B2-a (formula 4a), which are incorporated into the polymer chain through an ester group, resonate in the range of approximately 8.26 ppm, All chemical shifts herein are reported in "parts per million" (ppm) relative to trimethylsilane (TMS) as the reference.

[0045] Thus, preferred polycarbonates (wherein the structural units derived from hydroxybenzoic acid for components A, B1 and B2 are in all cases structural units derived from p-hydroxybenzoic acid, and for component B1 the structural units derived from hydroxybenzoic acid and having an esterified COOH function present as an end group are structural units derived from tert-butyl 4-hydroxybenzoate according to formula (2)) have a molecular weight of 1000 or more, as measured at room temperature in a solution of the polycarbonate in deuterated chloroform. 1 In the H NMR spectrum, it is characterized in that the ratio of the integrated intensity of the doublet signal in the range of approximately 8.14 ppm to the sum of the integrated intensities of the doublet signals in the range of approximately 8.05 ppm, 8.22 ppm and 8.26 ppm is in the range from 1.3 to 50, preferably in the range from 1.5 to 25, particularly preferably in the range from 1.8 to 10 and most preferably in the range from 2.0 to 5.0, where the chemical shifts are in each case referenced to tetramethylsilane (TMS).

[0046] In alternative embodiments, this ratio is in the range of 3-50, preferably in the range of 3-25, and most preferably in the range of 3-10.

[0047] These preferred polycarbonates are particularly preferably also characterized by their solubility in deuterated chloroform at room temperature. 1 It has the further feature that in the H NMR spectrum, the ratio of the sum of the integrated intensities of the doublet signals in the range of approximately 8.22 ppm and 8.26 ppm to the sum of the integrated intensities of the doublet signals in the range of approximately 8.14 ppm, 8.22 ppm and 8.26 ppm is less than 0.3, preferably less than 0.2, wherein the chemical shifts are in each case referenced to tetramethylsilane (TMS).

[0048] These preferred polycarbonates are particularly preferably also characterized by their solubility in deuterated chloroform at room temperature. 1In the H NMR spectrum, the ratio of the sum of the integrated intensities of the doublet signals in the range of approximately 8.14 ppm to the sum of the integrated intensities of the doublet signals in the range of approximately 8.14 ppm and 8.05 ppm is greater than 0.75, preferably greater than 0.9, where the chemical shifts are in each case referenced to tetramethylsilane (TMS).

[0049] In a preferred embodiment, the polycarbonate further contains structural units derived from a monophenol (i.e., an aromatic compound having only one phenolic OH functional group) that does not contain a carboxy functional group or a carboxy derivative functional group as an end group, as component C. The monophenol from which component C is derived is preferably phenol or an alkyl-, aryl-, alkylaryl- and / or halogen-substituted phenol, particularly preferably phenol or a C1-C 12 -alkylphenol, more preferably phenol or p-tert-butylphenol, most preferably p-tert-butylphenol.

[0050] It is further possible to use, for example, p-chlorophenol, 2,4,6-tribromophenol, 4-(2,4,4-trimethylpentyl)phenol, 4-(1,1,3,3-tetramethylbutyl)phenol, 3,5-di-tert-butylphenol, p-isooctylphenol, p-tert-octylphenol, p-dodecylphenol and 4-(3,6-dimethyl-3-heptyl)phenol.

[0051] In a preferred embodiment, the monophenols mentioned herein that do not contain a carboxy or carboxy derivative functionality are used as further chain terminators in the preparation of the polycarbonates according to the invention.

[0052] It is also possible to use mixtures of two or more monophenolic chain terminators not containing a carboxy or carboxy derivative functionality.

[0053] It is further preferred that component C is present in the polycarbonate according to the invention in a molar proportion of 20 mol % to 90 mol %, particularly preferably 40 mol % to 85 mol %, more preferably 45 mol % to 80 mol %, particularly preferably 50 mol % to 75 mol %, based on the sum of the molar proportions of components A, B1, B2, i.e. B2-a and B2-b, and of the molar proportion of component C totalling 100 mol %. These proportions make it possible, on the one hand, to achieve sufficient copolymer formation between the polycarbonate and the blending partners, and, on the other hand, to avoid undesired crosslinking reactions, which are presented again below.

[0054] The amount of component C in the polycarbonate and its molar ratio relative to the total of the molar ratios of components A, B1, B2 and C being 100 mol %, are 1 It can be spectroscopically quantified by H NMR. In the particularly preferred case where component C is a structural unit derived from p-tert-butylphenol, the NMR signal of the three methyl groups in the tert-butyl radical in the structural unit derived from p-tert-butylphenol is particularly suitable for this, for example. This is a singlet with a chemical shift in the range of approximately 1.32 ppm, which is assigned to nine protons, and is referenced to trimethylsilane.

[0055] The polycarbonates according to the invention also As component A, a plurality of structural units derived from structurally distinct hydroxybenzoic acids and having free COOH functional groups present as end groups, As component B1, a plurality of different structural units having an esterified COOH function present as a terminal group, which are distinguishable both with respect to the structural nature of the hydroxybenzoic acid and with respect to the structural nature of the tertiary alcohol used to form the ester, As component B2, a plurality of structural units derived from structurally distinct hydroxybenzoic acids which are incorporated into the polymer chain via ester or anhydride groups, and / or As component C, a plurality of structural units derived from structurally distinct hydroxybenzoic acids that do not contain a carboxy functional group or a carboxy derivative functional group as a terminal group; It may also contain:

[0056] As a result, for all ranges of amount ratios of these structural units listed in this application, the molar amounts of component A, component B1, component B2 and component C used to calculate the corresponding ratios are in each case the sum of all molar amounts of structurally distinct components A, B1, B2 and C.

[0057] The polycarbonate preferably has a weight average molecular weight M of 5000 g / mol to 40000 g / mol, more preferably 7000 g / mol to 35000 g / mol, particularly preferably 10000 g / mol to 30000 g / mol, measured by GPC (gel permeation chromatography) in methylene chloride at room temperature using BPA polycarbonate standards. w has.

[0058] For the use of the polycarbonates according to the invention as moulding compounds for producing moulded parts or as constituents of moulding compounds for producing moulded parts, the polycarbonates according to the invention preferably have weight-average molecular weights M of 18 000 g / mol to 40 000 g / mol, more preferably 20 000 g / mol to 35 000 g / mol, particularly preferably 24 000 g / mol to 32 000 g / mol, measured by GPC (gel permeation chromatography) at room temperature in methylene chloride using BPA polycarbonate standards. w has.

[0059] For the use of the polycarbonates according to the invention for the preparation of block copolymers containing blocks of aromatic polycarbonates and blocks of polymers which are immiscible with said aromatic polycarbonates, with regard to the efficiency of these block copolymers as compatibilizers in thermoplastic polymer compositions containing aromatic polycarbonates and said polymers which are immiscible with said aromatic polycarbonates, it is possible to obtain weight average molecular weights M of 5000 g / mol to 25000 g / mol, more preferably 7000 g / mol to 20000 g / mol, particularly preferably 8000 g / mol to 18000 g / mol and most preferably 10000 g / mol to 15000 g / mol, measured by GPC (gel permeation chromatography) at room temperature in methylene chloride using BPA polycarbonate standards. w It may be advantageous and preferable to use polycarbonates according to the invention which have

[0060] Different individual acid numbers, different ratios of A / B, different ratios of B2 / (A+B2), different ratios of A / (A+B1), and / or different individual weight average molecular weights M w When a mixture of two or more polycarbonates having the above-mentioned acid number, the ratio of A / B, the ratio of B2 / (A+B2), the ratio of A / (A+B1), and the weight average molecular weight M are used, the mixture may be any combination of the above-mentioned ranges. w has.

[0061] In general, the preparation of aromatic polycarbonates is known from the literature (for the preparation of aromatic polycarbonates see, for example, Schnell, "Chemistry and Physics of Polycarbonates", Interscience Publishers, 1964).

[0062] The preparation of aromatic polycarbonates according to the invention containing terminal COOH groups is carried out in a manner similar to that of US Pat. No. 5,399,633 by reaction of diphenols (aromatic diols) with phosgene by a phase interface process, using as monophenolic chain terminators an ester of hydroxybenzoic acid as described above or a mixture of two or more esters or a mixture of two or more structurally distinct hydroxybenzoic acids (when such mixtures are used, the esters used may differ with respect to the nature of the hydroxybenzoic acid and with respect to the nature of the alcohol used to form the ester), followed by liberation of terminal COOH groups (COOH functions).

[0063] In a preferred embodiment, the abovementioned further monophenols which do not contain a carboxy or carboxy derivative functionality are used as chain terminators in addition to the esters of hydroxybenzoic acids.

[0064] When using such further monophenolic chain terminators which do not contain carboxy or carboxy derivative functional groups, the aromatic polycarbonates produced not only contain components A, B1 and B2, but also contain structural units as component C which originate from the monophenolic chain terminator, most preferably p-tert-butylphenol.

[0065] When preparing the polycarbonates according to the invention, preferably, monophenolic chain terminators free of carboxy or carboxy derivative functional groups are used in a ratio of 20 mol% to 90 mol%, particularly preferably 40 mol% to 85 mol%, more preferably 45 mol% to 80 mol%, most preferably 50 mol% to 75 mol% in the mixture of these monophenolic chain terminators free of carboxy or carboxy derivative functional groups and chain terminators consisting of esters of hydroxybenzoic acid used as chain terminators. The difference resulting from 100 mol% in each case thus corresponds to the proportion of one or more esters of hydroxybenzoic acid. This difference is therefore preferably 10 mol% to 80 mol%, particularly preferably 15 mol% to 60 mol%, more preferably 20 mol% to 55 mol%, most preferably 25 mol% to 50 mol%.

[0066] If the content of hydroxybenzoic acid esters used in the chain terminator mixture is greater than the preferred ranges specified, the use of polycarbonates may lead to undesired crosslinking reactions during reactive compounding with the compounding partners, with the consequence that the thermoplastic processability of the reactive mixture is no longer assured. If the content of hydroxybenzoic acid esters used in the chain terminator mixture is less than the preferred ranges specified, the desired copolymer formation between the polycarbonate and the compounding partners may no longer occur to a sufficient degree to achieve the desired technical effect.

[0067] The molecular weight of the polycarbonates so produced can be specifically controlled over a wide range through variation of the ratio of monophenolic chain terminators to diphenols, in a manner well known to those skilled in the art.

[0068] The content of COOH groups in the aromatic polycarbonates can be specifically adjusted over a wide range through the ratio of the amounts used in the mixture of hydroxybenzoic acid ester chain terminators to the optionally used monophenolic chain terminators not containing carboxy or carboxy derivative functions, and through the conditions for the subsequent liberation of the COOH groups.

[0069] Terminal COOH groups (ie, hydroxybenzoic acid end groups) can be liberated from polycarbonates having hydroxybenzoic acid ester end groups, for example, through thermal end group pyrolysis or through acid ester cleavage.

[0070] A preferred process for liberating terminal COOH groups is thermal end group pyrolysis. The temperatures used are preferably 230°C to 265°C, particularly preferably 230°C to 260°C, most preferably 230°C to 255°C. The residence times at these temperatures are ≥ 15 s and ≤ 10 min, preferably ≥ 20 s and ≤ 5 min, particularly preferably ≥ 30 s and ≤ 2 min. Under these thermal conditions, the polycarbonate backbone is not appreciably modified and undesired side reactions are minimized. In particular by varying the temperature, but also the residence time at this temperature, it is possible to control the ratio of COOH end groups liberated from component B1, depending on component A, and also to undesired secondary / downstream products, depending on component B2. Component C generally remains unaffected in thermal end group pyrolysis.

[0071] The diphenols for the preparation of the aromatic polycarbonates and / or aromatic polyester carbonates preferably have the formula (5): [ka] (In the formula, A is a single bond, C1-C5 alkylene, C2-C5 alkylidene, C5-C6 cycloalkylidene, -O-, -SO-, -CO-, -S-, -SO2-, or a C6-C alkyl group optionally condensed with a further aromatic ring containing a heteroatom. 12Arylene, or formula (6) or formula (7): [ka] It is the radical of TIFF2024525481000006.tif25170, B is, in each case, C1 to C 12 alkyl, preferably methyl; halogen, preferably chlorine and / or bromine; x is, independently in each occurrence, 0, 1, or 2; p is 1 or 0, and R 5 and R 6 For each X 1 can be individually selected, each independently being hydrogen or C1-C6 alkyl, preferably hydrogen, methyl, or ethyl; X 1 is carbon, and m is an integer from 4 to 7, preferably 4 or 5, provided that at least one atom X 1 R on top 5 and R 6 It is a diphenol of the formula (wherein both are alkyl).

[0072] Preferred diphenols are hydroquinone, resorcinol, dihydroxydiphenols, bis(hydroxyphenyl)-C1-C5-alkanes, bis(hydroxyphenyl)-C5-C6-cycloalkanes, bis(hydroxyphenyl)ethers, bis(hydroxyphenyl)sulfoxides, bis(hydroxyphenyl)ketones, bis(hydroxyphenyl)sulfones, and α,α-bis(hydroxyphenyl)diisopropylbenzene, and their ring brominated and / or ring chlorinated derivatives.

[0073] Particularly preferred diphenols are 4,4'-dihydroxybiphenyl, bisphenol A, 2,4-bis(4-hydroxyphenyl)-2-methylbutane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfone, and their dibrominated or dichlorinated and tetrabrominated or tetrachlorinated derivatives, such as 2,2-bis(3-chloro-4-hydroxyphenyl)propane, 2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, or 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane. 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) is particularly preferred.

[0074] The diphenols can be used individually or in the form of any desired mixtures. The diphenols are known from the literature or can be obtained by literature methods.

[0075] In a preferred embodiment, the ratio of bisphenol A to the sum of all diphenols used in the preparation is at least 50 mol-%, particularly preferably at least 75 mol-%, most preferably at least 95 mol-%. Most preferably, only bisphenol A is used as diphenol in the preparation of component A.

[0076] The aromatic polycarbonates can be branched in a known manner, preferably by incorporating 0.01 mol % to 2.0 mol % of trifunctional or more than trifunctional compounds, e.g. compounds having three or more phenolic groups, relative to the total diphenols used.

[0077] The polycarbonates containing COOH end groups are preferably linear aromatic polycarbonates, more preferably based on bisphenol A, particularly preferably based exclusively on bisphenol A.

[0078] Further Polymers for Producing Copolymers The aromatic polycarbonates containing COOH end groups can be used to prepare copolymers, preferably block copolymers, more preferably block copolymers with vinyl (co)polymers or polyolefins.

[0079] Suitable polymers that can form copolymers with aromatic polycarbonates include at least one type of functional group selected from ester groups, hydroxy groups, carboxy groups, carboxylic anhydride groups and epoxy groups. Polymers containing ester groups, hydroxy groups or epoxy groups are preferred. It is particularly preferred that the polymer contains epoxy groups.

[0080] When an ester group is such a functional group, this group may be either a constituent of the polymer chain (polymer backbone), as in polyesters, or a functional group of a monomer that does not directly participate in the growing polymer chain, as is the case with acrylic acid polymers.

[0081] It is also possible to use mixtures of such polymers, which may in each case comprise polymers with the same functional groups or polymers with different functional groups.

[0082] In the context of the present invention, polymers containing carbonate groups, i.e. esters of carboxylic acids, are likewise considered as further polymers capable of forming block copolymers with aromatic polycarbonates, provided that they do not contain aromatic structural units.

[0083] The further polymer is preferably selected from the abovementioned functionalized vinyl (co)polymers and the abovementioned functionalized polyolefins and polyesters.

[0084] The functional group-containing vinyl (co)polymers according to the invention are preferably (co)polymers of at least one monomer from the group of (meth)acrylic acid (C1-C8)-alkyl esters (e.g. methyl methacrylate, n-butyl acrylate, tert-butyl acrylate), unsaturated carboxylic acids and carboxylic anhydrides, vinyl aromatics (e.g. styrene, α-methylstyrene), vinyl cyanides (unsaturated nitriles such as acrylonitrile, methacrylonitrile) and olefins (e.g. ethylene) and further vinyl monomers containing ester groups, hydroxy groups, carboxy groups, carboxylic anhydride groups and epoxy groups.

[0085] It is preferred if the further monomer glycidyl methacrylate is copolymerized with another monomer or monomers, for example to introduce epoxy groups.

[0086] These (co)polymers are resinous and rubber-free. (Co)polymers of this kind are known and can be prepared by free-radical polymerization, in particular by emulsion, suspension, solution or bulk polymerization.

[0087] Particularly suitable vinyl polymers contain structural units derived from glycidyl methacrylate.

[0088] A particularly suitable vinyl polymer is a copolymer of methyl methacrylate and glycidyl methacrylate.

[0089] Particularly suitable vinyl polymers further include styrene-acrylonitrile-glycidyl methacrylate terpolymer and styrene-methyl methacrylate-glycidyl methacrylate terpolymer.

[0090] Suitable polyesters may be aliphatic or aromatic polyesters.

[0091] In a preferred embodiment, the polyesters are aromatic, more preferably polyalkylene terephthalates. In a particularly preferred embodiment, they are reaction products of aromatic dicarboxylic acids or their reactive derivatives, such as dimethyl esters or anhydrides, and aliphatic, cycloaliphatic or araliphatic diols, and also mixtures of these reaction products.

[0092] Particularly preferred aromatic polyalkylene terephthalates comprise, based on the dicarboxylic acid component, at least 80% by weight, preferably at least 90% by weight, of terephthalic acid radicals, based on the diol component, and at least 80% by weight, preferably at least 90% by weight, of ethylene glycol and / or butane-1,4-diol radicals.

[0093] In addition to the terephthalic acid radical, preferred aromatic polyalkylene terephthalates may contain up to 20 mol %, preferably up to 10 mol %, of radicals of other aromatic or cycloaliphatic dicarboxylic acids having 8 to 14 carbon atoms or aliphatic dicarboxylic acids having 4 to 12 carbon atoms, such as phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, cyclohexanediacetic acid.

[0094] Preferred aromatic polyalkylene terephthalates are those which, in addition to the ethylene glycol and / or butane-1,4-diol radicals, contain up to 20 mol %, preferably up to 10 mol %, of other aliphatic diols having 3 to 12 carbon atoms or cycloaliphatic diols having 6 to 21 carbon atoms, such as, for example, propane-1,3-diol, 2-ethylpropane-1,3-diol, neopentyl glycol, pentane-1,5-diol, hexane-1,6-diol, cyclohexane-1,4-dimethanol, 3-ethylpentane-2,4-diol, 2-methylpentane-2,4-diol, 2,2,4-tri ... They may also contain radicals of methylpentane-1,3-diol, 2-ethylhexane-1,3-diol, 2,2-diethylpropane-1,3-diol, hexane-2,5-diol, 1,4-di(β-hydroxyethoxy)benzene, 2,2-bis(4-hydroxycyclohexyl)propane, 2,4-dihydroxy-1,1,3,3-tetramethylcyclobutane, 2,2-bis(4-β-hydroxyethoxyphenyl)propane and 2,2-bis(4-hydroxypropoxyphenyl)propane (DE-A-2 407 674, DE-A-2 407 776, DE-A-2 715 932).

[0095] Aromatic polyalkylene terephthalates can be branched by incorporating relatively small amounts of tri- or tetrahydric alcohols or tri- or tetrabasic carboxylic acids, for example according to DE-A-1 900 270 and US-A-3 692 744 (PS). Examples of preferred branching agents are trimesic acid, trimellitic acid, trimethylolethane and trimethylolpropane, and pentaerythritol.

[0096] Particularly preferred are aromatic polyalkylene terephthalates prepared exclusively from terephthalic acid and / or its reactive derivatives (eg, dialkyl esters thereof) and ethylene glycol and / or butane-1,4-diol, as well as mixtures of these polyalkylene terephthalates.

[0097] The aromatic polyalkylene terephthalates preferably used have a viscosity number of 0.4 dl / g to 1.5 dl / g, preferably 0.5 dl / g to 1.2 dl / g, measured in an Ubbelohde viscometer at 25° C. in phenol / o-dichlorobenzene (1:1 parts by weight) at a concentration of 0.05 g / ml according to ISO 307.

[0098] The aromatic polyalkylene terephthalates may be prepared by known methods (see for example Kunststoff-Handbuch, volume VIII, p. 695 et seq., Carl-Hanser-Verlag, Munich 1973).

[0099] It is likewise preferred that the further polymer is a functional group-containing polyolefin, preferably an epoxy-containing polyolefin, particularly preferably a polyolefin containing structural units derived from glycidyl methacrylate.

[0100] Polyolefins are produced by chain polymerization, for example by free radical or anionic polymerization. The monomers used are alkenes. Another name for alkenes is olefins. The monomers may be polymerized individually or as a mixture of various monomers. Preferred monomers are ethylene, propylene, 1-butene, isobutene, 1-pentene, 1-heptene, 1-octene and 4-methyl-1-pentene.

[0101] The polyolefins may be semi-crystalline or amorphous, linear or branched. The preparation of polyolefins is conventional and known to those skilled in the art.

[0102] The polymerization may be carried out, for example, at pressures between 1 bar and 3000 bar, at temperatures between 20° C. and 300° C., optionally with the use of a catalyst system. Examples of suitable catalysts include mixtures of titanium and aluminium compounds, and metallocenes.

[0103] The branching, crystallinity and density of polyolefins can vary over a wide range by varying the monomer composition, the type of isomer used as the monomer, the polymerization conditions and the catalyst system, measurements of which are also well known to those skilled in the art.

[0104] The functional groups are introduced into the polyolefin, for example, through copolymerization of a vinyl monomer containing the functional group with an olefin as described herein above, preferably by free radical polymerization. Suitable vinyl monomers are, for example, glycidyl methacrylate and methyl methacrylate.

[0105] An alternative mode of preparation is the free radical grafting of functional group-containing vinyl monomers onto the polyolefin.

[0106] Both manufacturing processes may use not only functional group-containing vinyl monomers, but also further vinyl monomers that do not contain functional groups, such as styrene.

[0107] The further polymer preferably has an average molecular weight (weight average M measured by GPC (gel permeation chromatography) against polystyrene standards) of 3000 g / mol to 300 000 g / mol, more preferably 5000 g / mol to 200 000 g / mol and particularly preferably 10 000 g / mol to 100 000 g / mol. w ).

[0108] The solvent for the GPC measurement is selected to be a good solvent for the further polymer, preferably at room temperature. If solubility of the selected solvent at room temperature is observed, the GPC is carried out at room temperature.

[0109] For example, tetrahydrofuran is a suitable solvent for vinyl (co)polymers, such as copolymers of methyl methacrylate and glycidyl methacrylate, styrene-acrylonitrile-glycidyl methacrylate terpolymers and styrene-methyl methacrylate-glycidyl methacrylate terpolymers. Suitable solvents for polyolefins containing structural units derived from glycidyl methacrylate include, for example, ortho-dichlorobenzene or 1,2-dichloroethane. Sufficient solubility is often achieved by high temperatures, for example 40°C, 60°C, 80°C, 100°C or 120°C. In this case, GPC is carried out at a temperature required to achieve sufficient solubility for GPC. When the polyolefin requires a temperature higher than 40°C to achieve sufficient solubility for GPC, it is preferred to use ortho-dichlorobenzene as the solvent.

[0110] Preparation of copolymers from the polycarbonates according to the invention Copolymers containing at least one polycarbonate block, preferably block copolymers comprising vinyl (co)polymers or polyolefins, most preferably block copolymers comprising PMMA, can be produced from the aromatic polycarbonates containing COOH end groups according to the invention and the further polymers mentioned above. The invention further provides such copolymers.

[0111] The preparation of such block copolymers is preferably carried out by a) I) an aromatic polycarbonate containing COOH end groups according to the present invention, II) a further functional group-containing polymer as described in the preceding paragraph; melting the composition comprising the compound through the introduction of thermal energy and / or mechanical shear; b) mixing and dispersing the different components of the composition with / in each other; c) solidifying the melt by cooling; d) pelletizing the material resulting from steps a) to c); and step (b) is carried out in a compounding apparatus selected from the group consisting of a single screw extruder, a co-rotating or counter-rotating twin screw extruder, a planetary roller extruder, an internal kneader and a co-kneader, preferably at a melt temperature of 230°C to 300°C.

[0112] Further components for producing thermoplastic molding compounds Both the COOH end group-containing aromatic polycarbonate according to the invention and the block copolymers produced therefrom can be used as components of thermoplastic molding compounds, preferably containing one or more additional polymers.These block copolymers are particularly suitable for use in thermoplastic molding compounds containing polycarbonate, preferably aromatic polycarbonate.These block copolymers are more preferably suitable for use in thermoplastic polymer blend molding compounds containing aromatic polycarbonate and at least one additional polymer with similar polarity to the polymer block that is bonded to the aromatic polycarbonate block in the block copolymer.These block copolymers are most preferably suitable for use in thermoplastic polymer blends containing aromatic polycarbonate and, as additional polymer, the same polymer that is bonded to the aromatic polycarbonate as the polymer block in the block copolymer.

[0113] These molding compounds may contain further components such as polymeric additives, processing aids and / or further polymeric components preferably selected from the group consisting of flame retardants, anti-drip agents, flame retardant synergists, smoke suppressants, lubricants and release agents, nucleating agents, polymeric and non-polymeric antistatic agents, conductivity additives, stabilizers (e.g. hydrolysis, heat ageing and UV stabilizers and also transesterification inhibitors), flow promoters, impact modifiers (with or without core-shell structure), polymeric compounding partners, fillers and reinforcing agents, and dyes and pigments.

[0114] Preferred polymeric blending partners are aromatic polycarbonates without COOH end groups, polyesters (such as preferably polyethylene terephthalate and polybutylene terephthalate), vinyl (co)polymers and polyolefins. In contrast to the polymers used to prepare the copolymers, they may not contain any functional groups, i.e. they may also not contain functional groups selected from ester, hydroxy, carboxy, carboxylic anhydride and epoxy groups. Suitable polymeric blending partners therefore include, for example, polystyrene, polyolefins, copolymers of ethylene and / or propylene and acrylates, styrene-acrylonitrile copolymers, styrene-methyl methacrylate copolymers and polymethyl methacrylate. These may be either rubber-free or rubber-containing. The latter applies, for example, to acrylonitrile-butadiene-styrene (ABS) or acrylonitrile-butyl acrylate-styrene (ASA) polymers.

[0115] The above mentioned further components are used in a total proportion of 0% to 40% by weight, preferably 0.1% to 30% by weight, more preferably 0.1% to 10% by weight, based on the thermoplastic composition.

[0116] To achieve a transparent thermoplastic composition, it is generally preferred / technically necessary to avoid certain further components, such as fillers and reinforcing agents, impact modifiers and rubber-containing compounding partners, or to limit their concentrations, and the concentrations of further components used elsewhere, to amounts significantly lower than specified above.

[0117] Production of molding compounds containing the polycarbonates and / or copolymers according to the invention and production of molded articles from such molding compounds The thermoplastic moulding compounds according to the invention can be prepared, for example, by mixing together in the melt the respective components, i.e. the polycarbonates according to the invention and / or the copolymers according to the invention and further polymer components, polymer additives and / or processing aids (i.e. the composition) at temperatures between 220°C and 320°C, preferably between 230°C and 300°C, particularly preferably between 240°C and 280°C and most preferably between 250°C and 270°C.

[0118] The mixing can be carried out in a conventional device, such as a single screw extruder, a co-rotating or counter-rotating twin screw extruder, a planetary roller extruder, an internal kneader or a continuous or discontinuous co-kneader. The composition is melt compounded or melt extruded therein to form a molding compound. In the context of this application, this process is generally referred to as compounding or melt compounding. The term "molding compound" is therefore understood to mean the product obtained when the components of the composition are melt compounded and melt extruded.

[0119] The mixing of the individual components of the composition can be carried out in known manner, either sequentially or simultaneously, at temperatures either at about 20° C. (room temperature) or higher, for example, some of the components may be introduced completely or partially through a main intake of an extruder, and the remaining components may be introduced completely or partially through a secondary extruder later in the compounding process.

[0120] The molding compounds of the invention can be used to produce any type of molded article. They may be produced, for example, by injection molding, extrusion and blow molding processes. A further form of processing is the production of molded articles by thermoforming from previously produced sheets or films.

[0121] It is also possible to meter the components of the composition directly into the conveying extruder of an injection molding machine, thus producing the molding compound according to the invention in the conveying extruder, and achieving direct processing into molded articles by suitable discharge of the molding compound into an injection mold (compounding or reactive compounding injection molding).

[0122] The present invention further relates to the use of the composition according to the invention or to the use of the molding compound according to the invention for producing a molded article, and also to a molded article obtainable from the composition according to the invention or from the molding compound according to the invention or to a molded article containing such a molding compound.

[0123] Examples of such molded articles are films, profiles, housing parts of any type, for example for household appliances, for example juice presses, coffee machines, mixers; office equipment, for example monitors, flat screens, notebooks, printers, copiers; sheets, pipes, electrical installation ducts, windows, doors and other profiles (interior and exterior applications) in the building sector, and also electrical and electronic components, for example switches, plugs and sockets, and component parts for commercial vehicles, especially those in the automotive sector. The compositions and molding compounds according to the invention are also suitable for producing the following molded articles or molded parts: interior parts for rail vehicles, ships, aircraft, buses and other motor vehicles, body components for motor vehicles, housings for electrical installations, including mini-transformers, housings for equipment for processing and transmitting information, housings and exteriors for medical equipment, massage equipment and housings therefor, children's ride-on toys, sheet-like wall members, housings for safety equipment, thermally insulated transport containers, molded parts for sanitary and bathroom equipment, protective grilles for ventilation openings and housings for garden equipment.

[0124] Further embodiments of the present invention are as follows.

[0125] 1. An aromatic polycarbonate, A) a structural unit derived from hydroxybenzoic acid and having a free COOH functional group present as an end group; B) A structural unit derived from hydroxybenzoic acid, Component B) is B1) structural units derived from hydroxybenzoic acid and having an esterified COOH functional group present as a terminal group, and B2) structural units derived from hydroxybenzoic acid which are incorporated into the polymer chain through ester or anhydride groups; and a structural unit selected from at least one representative of Contains An aromatic polycarbonate, wherein the molar ratio of the amount of component A to the amount of component B is in the range of 1.3 to 50.

[0126] 2. Aromatic polycarbonates according to embodiment 1, characterized in that they have an acid number of at least 0.3 mg KOH / g, determined at room temperature by potentiometric titration with ethanolic KOH solution according to DIN EN ISO 2114, method A, version 2002-6, in dichloromethane (DCM) / ethanol as solvent.

[0127] 3. The aromatic polycarbonate according to embodiment 2, having an acid value in the range of 0.5 mg KOH / g to 10 mg KOH / g.

[0128] 4. The aromatic polycarbonate according to any one of the above embodiments, wherein the molar ratio of the amount of Component A to the amount of Component B is in the range of 1.5 to 25.

[0129] 5. The aromatic polycarbonate according to any one of the above embodiments, wherein the molar ratio of the amount of Component A to the amount of Component B is in the range of 2.0 to 5.0.

[0130] 6. An aromatic polycarbonate according to any of the preceding embodiments, characterized in that the molar ratio of the amount of component B2 to the sum of the amounts of components A and B2 is less than 0.3.

[0131] 7. An aromatic polycarbonate according to any of the preceding embodiments, characterized in that the molar ratio of the amount of component B2 to the sum of the amounts of components A and B2 is less than 0.2.

[0132] 8. An aromatic polycarbonate according to any of the previous embodiments, characterized in that the molar ratio of the amount of component A to the sum of the amounts of components A and B1 is greater than 0.75.

[0133] 9. An aromatic polycarbonate according to any of the previous embodiments, characterized in that the molar ratio of the amount of component A to the sum of the amounts of components A and B1 is greater than 0.90.

[0134] 10. The aromatic polycarbonate according to any one of the above embodiments, further comprising, as component C, a structural unit derived from a monophenol that does not contain a carboxy functional group or a carboxy derivative functional group.

[0135] 11. The aromatic polycarbonate according to embodiment 10, wherein the monophenol is p-tert-butylphenol or phenol.

[0136] 12. The aromatic polycarbonate according to embodiment 10 or 11, in which component C is present in the polycarbonate in a molar ratio of 20 mol % to 90 mol % relative to the total molar ratios of components A, B1, B2 and C being 100 mol %.

[0137] 13. The aromatic polycarbonate according to embodiment 10 or 11, in which component C is present in the polycarbonate in a molar ratio of 50 mol % to 75 mol % relative to 100 mol % in total of the molar ratios of components A, B1, B2 and C.

[0138] 14. Weight average molecular weight M measured by GPC in methylene chloride at room temperature using BPA polycarbonate standard w is 5000 g / mol to 40000 g / mol.

[0139] 15. Weight average molecular weight M w 15. The aromatic polycarbonate according to embodiment 14, wherein the Molecular Weight (Mw) of the polycarbonate is from 24,000 g / mol to 32,000 g / mol.

[0140] 16.Weight average molecular weight M w is from 5000 g / mol to 25000 g / mol.

[0141] 17.Weight average molecular weight M w 15. The aromatic polycarbonate according to embodiment 14, wherein the MnO2 content is from 8000 g / mol to 18000 g / mol.

[0142] 18.Weight average molecular weight M w is from 10,000 g / mol to 15,000 g / mol.

[0143] 19. A method for producing an aromatic polycarbonate, comprising: (i) as a chain terminator 1. A process for producing aromatic polycarbonates containing end groups derived from hydroxybenzoic acid esters by phosgenation in the presence of an ester of hydroxybenzoic acid or a mixture of two or more esters of one or more structurally distinct hydroxybenzoic acids during a phase interface process or in an organic solution of an aromatic diol, comprising the steps of: in the preparation according to process step (i), not exceeding a temperature of 260° C. at any time; (ii) subjecting the end groups derived from the hydroxybenzoic acid ester in the product of process step (i) to thermal end group pyrolysis to remove alkenes, In process step (ii), the product from process step (i) is pyrolyzed by supplying thermal or mechanical energy in the temperature range of 230° C. to 265° C., and the resulting alkene is removed from the apparatus; A residence time in the temperature range of 230°C to 265°C is 15 seconds or more and 10 minutes or less; A method comprising:

[0144] 20. The method of embodiment 19, wherein the temperature in method step (ii) is from 230°C to 260°C.

[0145] 21. The method of embodiment 19, wherein the temperature in method step (ii) is from 230°C to 255°C.

[0146] 22. The method according to any one of embodiments 19 to 21, wherein the residence time is from 20 seconds to 5 minutes.

[0147] 23. The method according to any one of embodiments 19 to 21, wherein the residence time is from 30 seconds to 2 minutes.

[0148] 24. The process step (i) comprises reacting a hydroxybenzoic acid with a compound having the general structure (1): [ka] (wherein R1 and R2 are each independently hydrogen or an alkyl radical having 1 to 10 carbon atoms, an aryl radical or an alkylaryl radical, preferably hydrogen or an alkyl radical having 1 to 4 carbon atoms, particularly preferably hydrogen or a methyl radical, and most preferably both are a methyl radical; The method according to any of embodiments 19 to 23, wherein R3 and R4 independently of one another represent hydrogen or an alkyl radical having 1 to 10 carbon atoms, an aryl radical or an alkylaryl radical, preferably hydrogen or an alkyl radical having 1 to 4 carbon atoms, particularly preferably hydrogen or a methyl radical, most preferably both hydrogen), with an alcohol is used as an ester.

[0149] 25. The method of embodiment 24, wherein the alcohol is a tertiary alcohol.

[0150] 26. The method of embodiment 24, wherein the alcohol is tert-butanol.

[0151] 27. The method of any of embodiments 19-26, wherein the alkene is removed by application of negative pressure.

[0152] 28. The method according to any of embodiments 19 to 27, wherein in method step (ii), the product from method step (i) is melted in a compounding apparatus selected from the group comprising a single screw extruder, a co-rotating or counter-rotating twin screw extruder, a planetary roller extruder, a continuous or discontinuous internal mixer and a film truder by supplying thermal or mechanical energy and pyrolyzed at a melt temperature in the range of 230°C to 260°C, and the residence time of the melt in this temperature range is 30 seconds or more and 2 minutes or less.

[0153] 29. The method according to any one of embodiments 19 to 28 for producing the aromatic polycarbonate according to any one of embodiments 1 to 18.

[0154] 30. A polycarbonate produced by the method of any one of embodiments 19 to 28.

[0155] 31. A copolymer containing structural units derived from the aromatic polycarbonate according to any one of embodiments 1 to 18 or 30.

[0156] 32. The copolymer of embodiment 31, containing at least one polycarbonate block.

[0157] 33. The copolymer of embodiment 31, comprising at least one polycarbonate block and at least one vinyl polymer or polyolefin block.

[0158] 34. The copolymer of embodiment 31, containing at least one polycarbonate block and at least one polymethyl methacrylate block.

[0159] 35. A thermoplastic molding compound containing the copolymer according to any one of embodiments 31 to 34, or the aromatic polycarbonate according to any one of embodiments 1 to 18 or embodiment 30.

[0160] 36. Use of an aromatic polycarbonate according to any one of embodiments 1 to 18 or 30 for producing a copolymer containing at least one polycarbonate block.

[0161] 37. Use of an aromatic polycarbonate according to any one of embodiments 1 to 18 or 30 for producing a block copolymer containing at least one polycarbonate block and at least one vinyl polymer or polyolefin block.

[0162] 38. A method for producing a copolymer containing at least one polycarbonate block, comprising the steps of: a) I) An aromatic polycarbonate according to any one of embodiments 1 to 18 or 30; II) a further polymer containing at least one type of functional group selected from ester groups, hydroxy groups, carboxy groups, carboxylic anhydride groups and epoxy groups; A composition comprising Melting through the introduction of thermal energy and / or mechanical shear; b) mixing and dispersing the different components of the composition with / in each other; c) solidifying the melt by cooling; d) pelletizing the coagulated polymer blend resulting from steps (a) to (c); Including, A process wherein step (b) is carried out in a compounding apparatus selected from the group consisting of a single screw extruder, a co-rotating or counter-rotating twin screw extruder, a planetary roller extruder, an internal kneader or a co-kneader at a melt temperature of 230°C to 300°C.

[0163] 39. The method of embodiment 38, wherein component II) is a vinyl polymer or polyolefin containing structural units derived from glycidyl methacrylate.

[0164] 40. A molded article containing a copolymer obtainable by the method according to embodiment 38 or 39, or containing a molding compound according to embodiment 35. EXAMPLES

[0165] Preparation of polycarbonate precursor (PC-1) Bisphenol A was subjected to polycondensation reaction with phosgene in a mixture of methyl chloride and chlorobenzene as solvent in the presence of a mixture of chain terminators consisting of p-tert-butylphenol and tert-butyl 4-hydroxybenzoate in an interfacial process in a continuously operated laboratory reactor.

[0166] In the context of this synthesis, 72.2 g / h of gaseous phosgene were dissolved in 959 g / h of an organic solvent mixture consisting of 50% by weight of methylene chloride and 50% by weight of chlorobenzene at -7°C. The phosgene solution thus produced was contacted with 907 g / h of an aqueous 15% by weight alkaline bisphenol A solution thermostated at 30°C. To this end, the alkaline bisphenol A solution was forced into the phosgene solution through a stainless steel filter with a pore size of 90 μm and thus dispersed therein. In the bisphenol A solution, 2 moles of NaOH were used per mole of bisphenol A. The reaction mixture was reacted in a Fink HMR040 mixing pump thermostated at 25°C until the phosgene was completely reacted. Thereafter, 4.11 g / h of a mixture of 50 mol % p-tert-butylphenol and 50 mol % tert-butyl 4-hydroxybenzoate were added as chain terminator, i.e. in the form of a 3% by weight solution in a solvent mixture composed of 50% by weight methylene chloride and 50% by weight chlorobenzene.

[0167] The reaction mixture thus obtained was further reacted with 66.52 g / h of 32% by weight aqueous sodium hydroxide in a second Fink HMR040 mixing pump thermostated at 25° C. Downstream of this were two stirred tanks, working in flooded mode, equipped with baffles, each with a residence time of 600 seconds, each followed by a gear pump, which both transports and further disperses the reaction mixture. After the first pump, i.e. upstream of the second stirred tank, 0.679 g / h of a 10% by weight solution of N-ethylpiperidine in chlorobenzene was added as catalyst. At the end of the reaction, the pH was about 11.5. In a phase separation vessel, the organic phase was separated from the aqueous phase of the two-phase reaction mixture, and the organic phase was washed with 0.1% by weight aqueous HCl to remove the catalyst.

[0168] This was followed by washing with demineralized water to remove salt residues.The polymer solution washed in this manner was precipitated into an organic solvent and dried overnight at 120° C. in a vacuum oven.

[0169] Preparation of polycarbonates according to the invention by end group pyrolysis of polycarbonate precursor PC-1 The liberation of COOH end groups by thermal end group pyrolysis of polycarbonate precursor PC-1 produced according to the above-mentioned method through removal of protecting groups in the form of isobutylene gas was carried out in a continuous Process 11 twin screw extruder (Thermofischer Scientific, Karlsruhe, Germany) with a screw configuration having three mixing zones and a length to diameter (L / D) ratio of 40. Various inventive polycarbonate examples and comparative examples were carried out at various melt temperatures ranging from 227°C to 288°C, measured through a thermocouple installed near the die exit in the last barrel element of the extruder. The melt temperatures resulted from the introduction of mechanical energy through the kneading elements and thermal energy through the heating of the extruder barrel. The extruder barrel is divided into eight separate and independently heatable zones. The three kneading zones were in the transition between heating zone 3 and heating zone 4, in heating zone 5, and in the transition between heating zone 6 and heating zone 7. The raw material intake was in heating zone 1. Furthermore, the exit die is separately heatable. The barrel and die temperatures in the barrel zones were thermostated to different temperatures to adjust for different melt temperatures detected through a thermocouple installed near the die exit in the last barrel element of the extruder (see Table 1). The first barrel (raw material intake zone) was unheated in all cases, zone 2 was heated to a target temperature of 70°C in all cases, and zones 4 to 8 were heated to the same respective target temperatures listed in Table 1 in all cases. The same polycarbonate precursor (PC-1) was used as the input raw material in all cases. The extruder was operated in all cases with a throughput of about 300 g / h and a feed rate of 175 min -1The extruder was operated at a speed of 100 rpm. Under these process conditions, isobutylene gas liberated in the extruder was continuously withdrawn from the extruder through a vent dome in the penultimate (seventh) heating zone by applying a negative pressure of about 100 mbar (absolute). In all cases, these process conditions resulted in a residence time of the polycarbonate in the extruder of about 70 seconds. The barrel temperatures used in the extruder heating zones for the inventive and comparative polycarbonates produced separately, as well as the melt temperatures measured by a thermocouple placed near the die exit in the last barrel element of the extruder, are evident from Table 1.

[0170] Table 1: Target temperatures set in the different heating zones of the barrel and at the exit die of the twin-screw extruder, and melt temperatures measured near the die exit, in the production of the polycarbonates of the invention and the comparative polycarbonates.

[0171] [Table 1]

[0172] Polycarbonate structural properties The molecular weight of the polycarbonate was determined by gel permeation chromatography (GPC) in methylene chloride at room temperature using BPA polycarbonate as a calibration standard. The FTIR detector was set to 1775 cm -1 A wavelength selected for BPA polycarbonate was used.

[0173] The analysis of the polycarbonates with regard to the content of structural units according to components A, B1, B2-a, B2-b and C was carried out in deuterated chloroform as solvent at room temperature. 1 This was carried out by 1 H NMR spectroscopy (see Table 2).

[0174] The integrated signal intensity of each NMR signal divided by the number of protons involved in the signal is proportional to the molar content of each structural unit. The corresponding ratios of the normalized signal intensities were then used to determine the molar ratios of the corresponding structural units according to the various characteristics of the polycarbonates of the present invention.

[0175] The acid numbers of polycarbonates were determined at room temperature by potentiometric titration with ethanolic KOH solution according to DIN EN ISO 2114, method A, version 2002-6, in dichloromethane (DCM) / ethanol as solvent. For this purpose, the polycarbonates to be investigated were dissolved at room temperature in 50 mL of dichloromethane at a concentration of 10 g / L. 5 mL of ethanol were added to the sample solution before potentiometric titration with 0.1 N ethanolic KOH.

[0176] The structural characteristics thus determined of the polycarbonates produced are summarized in Table 2.

[0177] Table 2: Results of structural characterization of produced polycarbonates

[0178] [Table 2]

[0179] Combining the data in Table 2 with the process parameters in Table 1, it is clear that the structure of the produced polycarbonates is surprisingly strongly dependent on the thermal conditions (especially the melting temperature) in the end group pyrolysis step (ii). Polycarbonates with high A / B ratios are obtained at relatively narrow melting temperature ranges (PC-3 and PC-4), while those with lower melting temperatures, e.g. 227° C. (PC-2 * ), and 270℃ (PC-5 * ), 274℃(PC-6 * ) and 288°C (PC-7 * ), as well as the product obtained directly in process step (i), i.e. without end group pyrolysis process step (ii) (PC-1 *) results in a significantly lower A / B ratio. PC-4 shows a further improved A / B ratio than PC-3. PC-4 also shows a further improved A / (A+B1) than PC-3, as a measure of the degree of desired removal of isobutylene from the tert-butyl ester protecting groups to liberate terminal COOH groups. The B2 / (A+B2) ratio, as a measure of the degree of conversion of COOH end groups formed during the undesired subsequent transesterification reaction, is approximately the same for PC-3 and PC-4.

[0180] Production of molding compounds from the polycarbonates according to the invention The polycarbonates according to the invention and the comparative polycarbonates were used to prepare PC / PMMA molding compounds through a reactive extrusion process. For this purpose, the polycarbonates were first ground to a powder and premixed with a similarly ground methyl methacrylate-glycidyl methacrylate copolymer (PMMA-GMA) in a ratio of 80% by weight of the respective polycarbonate to 20% by weight of PMMA-GMA to obtain a homogeneous powder mixture. PMMA-GMA had a content of 1.0% by weight of structural units derived from glycidyl methacrylate prepared by free radical polymerization and had a weight average molecular weight M of 60000 g / mol, measured by gel permeation chromatography at room temperature in tetrahydrofuran as solvent against polystyrene calibration standards. w The epoxy equivalent weight of this PMMA-GMA copolymer was determined to be 0.32 wt. % in dichloromethane at room temperature according to DIN EN 1877-1 (12-2000 version).

[0181] Polycarbonate of the invention (PC-8) and non-invention polycarbonate (PC-6 * For specific adjustment of the different A / B ratio mixtures at these different mixing ratios, the two polycarbonates were further mixed into a comparative PC / PMMA molding compound PC / PMMA-4 * ~PC / PMMA-6 * It was also used as a polycarbonate component for the preparation of

[0182] Polycarbonate PC-8 was likewise obtained from the precursor PC-1 by thermal end group pyrolysis, PC-8 having an acid number of 2.4 mg KOH / g, determined at room temperature by potentiometric titration with ethanolic KOH solution according to DIN EN ISO 2114, method A, version 2002-6, in dichloromethane (DCM) / ethanol as solvent. 1 Using H NMR spectroscopy, the ratio A / B was determined to be 1.8, the ratio B2 / (A+B2) to be 0.28, the ratio B1 (A+B1) to be 0.85, and the ratio C / (A+B+C) to be 0.55.

[0183] Thermoplastic PC / PMMA molding compounds with the composition shown in Table 3 were mixed in a mixing chamber with a melt temperature of 260°C, a throughput of about 300 g / h, and a running time of 125 min. -1 Compounding was performed in a Process 11 continuous twin-screw extruder (Thermofischer Scientific, Karlsruhe, Germany) with a screw configuration with a speed of 1000 rpm and a pressure of 100 mbar absolute. These conditions resulted in a residence time of about 90 seconds. After discharge through a die plate, the molten strands were cooled and thus solidified, and subsequently pelletized. For the compounding operation, a powder mixture of the PC and PMMA components was metered into the feed zone of the twin-screw extruder through a volumetric means.

[0184] Production of molded articles from molding compounds containing polycarbonates according to the invention and their technical evaluation Thermoplastic PC / PMMA moulding compounds made from the compositions listed in Table 3 were used to produce round plates with a diameter of 25 mm and a thickness of 1 mm in a Polystat 200 laboratory hot press from Servitec Maschinenservice GmbH (Wustermark, Germany) at a temperature of 260° C., a pressure of 100 bar and a total press time of 4 minutes.

[0185] The transparency and homogeneity of the molded articles thus produced were first evaluated by visual means. The corresponding wavelength-dependent total transmittance was further determined according to DIN 5033-7 (2014) and used to calculate the transmittance value Y(D65, 10°) according to DIN EN ISO 11664-3 (2013) with light type D65 and observer angle of 10°.

[0186] The ductility of the molding compounds was also evaluated in impact tests at room temperature for these hot-pressed round plates with a diameter of 25 mm and a thickness of 1 mm. Measurements were performed with a custom-made drop impact tester (drop mass 1.86 kg, support diameter 15 mm, mandrel diameter (hemisphere) 7 mm). The drop height of the drop mass was systematically varied to determine the maximum drop height at which the test specimen was not penetrated / demonstrated any damage and the maximum drop height at which the test specimen showed ductile failure with stable crack propagation.

[0187] The data in Table 3 show that only the inventive polycarbonate PC-3 allowed the production of a PC / PMMA molding compound that could be processed into homogeneous transparent molded articles with high transmittance. This molding compound also has excellent ductility at room temperature. The non-inventive comparative polycarbonate PC-6, which was end-group pyrolyzed at a higher melt temperature, * It was not possible to achieve a transparent molded article. Non-inventive comparative polycarbonate PC-1 from process step (i) * However, it was likewise not possible to achieve homogeneous transparent molded articles. The PC / PMMA molding compounds made with this polycarbonate resulted in milky and unevenly molded articles. Due to the specific variation of the A / B ratio, which ranged up to 0.9, the molding compound made with the polycarbonate mixture PC / PMMA-4 * ~PC / PMMA-6 * None of these methods have been able to produce a transparent molded article having high light transmittance (i.e., illumination transmittance).

[0188] Table 3: PC / PMMA molding compounds

[0189] [Table 3]

Claims

1. An aromatic polycarbonate comprising: A) a structural unit derived from hydroxybenzoic acid and having a free COOH functional group present as a terminal group; and B) a structural unit derived from hydroxybenzoic acid, wherein component B) is B1) a structural unit derived from hydroxybenzoic acid and having an esterified COOH functional group present as a terminal group, and B2) a structural unit derived from hydroxybenzoic acid incorporated into the polymer chain through an ester group or an acid anhydride group, a structural unit selected from at least one representative of and containing an aromatic polycarbonate wherein the molar ratio of the amount of component A to the amount of component B is in the range of 1.3 to 50.

2. The aromatic polycarbonate according to claim 1, characterized by an acid value in the range of 0.5 mg potassium hydroxide (KOH) / g to 10 mg potassium hydroxide (KOH) / g, determined in dichloromethane (DCM) / ethanol as a solvent according to DIN EN ISO 2114, method A, 2002 - 6 version, by potentiometric titration using an ethanolic potassium hydroxide (KOH) solution at room temperature.

3. The aromatic polycarbonate according to claim 1 or 2, characterized in that the molar ratio of the amount of component B2 to the total amount of components A and B2 is less than 0.

3.

4. The aromatic polycarbonate according to claim 1 or 2, characterized in that the molar ratio of the amount of component A to the total amount of components A and B1 is greater than 0.

75.

5. Further containing a structural unit derived from a monophenol that does not contain a carboxy functional group or a carboxy derivative functional group as component C, and component C is present in the polycarbonate in a molar ratio of 20 mol% to 90 mol% with respect to a total of 100 mol% of the molar ratios of components A, B1, B2, and C. The aromatic polycarbonate according to claim 1 or 2.

6. A method for producing an aromatic polycarbonate, comprising: (i) As a chain terminator, producing an aromatic polycarbonate containing terminal groups derived from hydroxybenzoic acid esters by phosgenation in a phase interface process or in an organic solution of an aromatic diol in the presence of an ester of hydroxybenzoic acid or a mixture of two or more esters of one or more structurally distinct hydroxybenzoic acids, in the production described in method step (i), a step that does not exceed a temperature of 260 °C at any time. (ii) A step of thermally decomposing the terminal group derived from the hydroxybenzoic acid ester in the product by the method engineering (i) to remove alkenes, wherein in the method engineering (ii), the product by the method engineering (i) is thermally decomposed by supplying thermal energy or mechanical energy in a temperature range of 230°C to 265°C, and the generated alkenes are removed from the apparatus, a step in which the residence time in the temperature range of 230°C to 265°C is 15 seconds or more and 10 minutes or less; A method comprising: **Claim 7** The method engineering (i) is a hydroxybenzoic acid and the general structure (1): 【Chemical 1】 (wherein R １ , R ２ , R ３ and R ４ each independently represents hydrogen or an alkyl radical, aryl radical or alkylaryl radical having 1 to 10 carbon atoms), the method according to claim 6, using an ester with an alcohol. **Claim 8** In the method engineering (ii), the product by the method engineering (i) is melted by supplying thermal energy or mechanical energy in a compounding apparatus selected from the group consisting of a single-screw extruder, a co-rotating or counter-rotating twin-screw extruder, a planetary roller extruder, a continuous or discontinuous internal mixer, and a film truder, thermally decomposed at a melting temperature in the temperature range of 230°C to 260°C, and the residence time of the melting in this temperature range is 30 seconds or more and 2 minutes or less. The method according to claim 6 or 7. **Claim 9** A copolymer containing a structural unit derived from the aromatic polycarbonate according to claim 1 or 2. **Claim 10** A method for producing a copolymer containing at least one polycarbonate block, comprising: a) I) The aromatic polycarbonate according to claim 1 or 2, and II) A further polymer containing at least one type of functional group selected from the group consisting of an ester group, a hydroxy group, a carboxy group, a carboxylic anhydride group, and an epoxy group, A composition containing a step of melting through the introduction of thermal energy and / or mechanical shearing; b) A step of mixing and dispersing different components of the composition with each other and into each other; c) A step of solidifying the melt by cooling; d) A step of pelletizing the solidified polymer blend resulting from steps (a) to (c), comprising wherein step (b) is carried out at a melting temperature of 230°C to 300°C in a compounding apparatus selected from the group consisting of a single-screw extruder, a co-rotating or counter-rotating twin-screw extruder, a planetary roller extruder, an internal mixer, or a co-mixer.

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