Pyrolysis of a combination of polycarbonate-containing materials and phosphorus-containing organic compounds to recover raw materials - Patents.com

Abstract

The present invention relates to a method for pyrolysis of polycarbonate-containing materials to recover raw materials, the method comprising at least the following steps: (a) introducing into a reactor a material to be pyrolyzed, the material comprising at least a polycarbonate-containing compound and a total amount of phosphorus organic compounds, said total amount contributing to a proportion of at least 0.01% by weight of phosphorus having a formal oxidation number of +5 relative to the total weight of the material to be pyrolyzed; (b) decomposing at least the material to be pyrolyzed introduced into the reactor in step (a) at a temperature of 300° C. to 700° C., and recovering products present in the gas phase as pyrolysis products and products present in the non-gas phase as pyrolysis products. The pyrolysis process comprises the steps of: (i) the amount of oxygen gas in the reactor during decomposition is 2.0% by volume or less, based on the total volume of gas present in the reactor; (ii) discharging the pyrolysis product from the reactor during decomposition; and (iii) discharging the pyrolysis residue from the reactor; (c) cooling the removed pyrolysis product to a temperature below 300° C., while obtaining a pyrolysis product selected from a pyrolysis condensate, a pyrolysis sublimate, or a mixture thereof; and (d) optionally processing the pyrolysis product. When the process is carried out in a correspondingly designed device, the raw material for producing polycarbonate-containing materials, in particular phenols, can be recovered in higher yields from the material subjected to pyrolysis.

Description

[Background technology]

[0001] Polycarbonate blends, such as polycarbonate resins or polycarbonate composite resins, are used as materials for consumer goods. The corresponding polycarbonate resins or polycarbonate composite resins are made by blending polycarbonate with other polymers, such as blending polycarbonate with acrylonitrile-butadiene-styrene (ABS). These polycarbonate-containing materials have excellent properties such as impact resistance, flowability, toughness, and flame retardancy, and are therefore used in many applications, such as electronic devices and automobiles.

[0002] The polycarbonate resins and polycarbonate composite resins mentioned above enter the market as components of many products and then accumulate in waste as useful materials at the end of the product's useful life. Most of the old products are sent to the landfill and replaced by new products. The total amount of plastic waste generated by this is increasing year by year. Approximately 60% of this total amount of waste is disposed of by incineration or landfill.

[0003] Incineration of plastic waste releases CO2 into the atmosphere, contributing to global warming. Due to its low density, plastic waste occupies a large volume in landfills, which can lead to general pollution of rivers and oceans. It is therefore important to develop efficient recycling methods that can solve the waste problem and at the same time protect fossil resources.

[0004] Since the above-mentioned polycarbonate (composite) resins account for approximately 8% of the polymer market, polycarbonate recycling has not been a focus of development so far. However, in the future, as the plastic market will continue to grow, it will be important to develop recycling technologies for all types of polymers in order to simultaneously reduce CO2 emissions and protect fossil energy sources.

[0005] The processes for recycling plastic waste can be broadly divided into three categories: (1) Mechanical recycling: Here, the plastic waste can be remelted as is and then reused. This is possible, for example, for very pure PC waste. (2) Chemical and thermochemical recycling: Here, plastic waste is depolymerized into monomers or broken down into smaller molecules to obtain useful chemical raw materials. (3) Thermal recycling: Here, plastic waste is converted into off-gas and thermal energy.

[0006] The chemical raw materials obtained from thermochemical recycling can be used to synthesize new synthetic resins or other chemical products.

[0007] Thermochemical recycling is called pyrolysis. Most often, pyrolysis is used for packaging waste, obtaining pyrolysis oil in the form of a drop-in solution, which is used as a kind of recycled naphtha in known refining processes using crackers. Little is known about the pyrolysis of polycarbonate in this pyrolysis process.

[0008] The use of catalysts or additives in the pyrolysis process can reduce the operating temperature, shorten the reaction time, increase the cracking efficiency, and limit the product distribution, making the process more efficient.

[0009] The use of metal halide salts as catalysts, especially copper chloride and iron chloride catalysts, made it possible to produce more phenolic compounds in the pyrolysis of polycarbonate at 600 °C than without the use of catalysts (Non-Patent Document 1). In addition, the catalytic pyrolysis of polycarbonate was optimized with various metal chloride compounds with the aim of reducing the carbonized residue (Non-Patent Document 2). Since the uncatalyzed pyrolysis proceeds very slowly at 400 °C, the influence of the catalyst was determined at 400 °C (1 h). The choice of metal chloride had a significant impact on the pyrolysis. NaCl, CrCl3, CuCl3 and AlCl3 did not improve the pyrolysis rate, whereas SnCl2 and ZnCl2 decomposed polycarbonate with a weight loss of more than 80%.

[0010] The use of metal salts as catalysts could also improve the product distribution in the pyrolysis of polycarbonate: whereas the liquid products in the pyrolysis of uncatalyzed polycarbonate contained 11 different products, the mixtures using ZnCl2 or SnCl2 as catalysts contained only seven major products, including bisphenol A, phenol, and diphenyl ether, with smaller amounts of impurities.

[0011] Catalysts consisting of metal oxides and zeolites with various porosities and acidic / basic properties are also known for the thermal decomposition of polycarbonate-containing materials (Non-Patent Documents 3 and 4).

[0012] By using basic catalysts such as CaO and MgO, the temperature of pyrolysis could be significantly reduced to 400-450°C, and a liquid fraction containing a high proportion of phenolic compounds was simultaneously produced (Non-Patent Documents 5 and 6). It was possible to demonstrate that BPA and CO2 were slowly released from polycarbonate at 440°C from a mixture of polypropylene (PP), acrylonitrile-butadiene-styrene (ABS), high impact polystyrene (HIPS), and polycarbonate.

[0013] Under the influence of alkaline earth metal oxides and hydroxides (MgO and Mg(OH)2), steam pyrolysis of pure polycarbonate could achieve better efficiency and a higher BPA yield (78%) at 300°C, while heating to 500°C with MgO produced a high percentage of phenol (84%) (Non-Patent Document 7, Non-Patent Document 8).

[0014] Patent Document 1 describes a method for depolymerizing polycarbonate using supercritical or subcritical water. This method produces a high-purity dihydroxy component (BPA), a component of polycarbonate, in high yield. This depolymerization method does not involve the use of organic solvents, so it has a low environmental impact. This method shows a high decomposition rate and produces almost no by-products.

[0015] None of the pyrolysis processes described in the prior art are suitable for industrial or commercial use, as they are primarily intended for use as microgram-scale pyrolysis for analytical purposes. Thus, the pyrolysis presented in the prior art is in each case carried out in a pyrolysis apparatus that is not suitable for industrial or commercial use.

[0016] In particular, for the pyrolysis of larger amounts of polycarbonate-containing materials, which contain other components in addition to polycarbonate, new processes are required with suitable reactors that can reduce the influence of other components on the results of the pyrolysis of polycarbonate. For example, it has been found that the pyrolysis of polycarbonate-containing compounds containing oxygen-functionalized aromatic structural fragments (more specifically, oxygen-functionalized diphenyl alkylene structural fragments) leads to the formation of a mixture of hydroxyl-functionalized aromatic compounds, among others. For further use, this mixture must be separated and the obtained separated products must be fed, if possible, to various recycling processes. It is therefore desirable to control the pyrolysis process in such a way that pyrolysis products containing a high content of aromatic hydroxy compounds, such as phenol, that can be reused for the production of polycarbonate can be obtained with high selectivity from polycarbonate-containing materials. Up to now, the desired proportion of phenol has been obtained under standard pyrolysis conditions of at least 600 ° C., mainly using zeolite catalysts with long residence times. [Prior art documents] [Patent documents]

[0017] [Patent Document 1] US Patent Application Publication No. 2007 / 0185309 [Non-patent literature]

[0018] [Non-Patent Document 1] M. Blazso, J. Anal. Appl. Pyrolysis, 1999, 51, 73-88 [Non-Patent Document 2] J. Chiu et al., Waste Management., 2006, 26, 252-259 [Non-Patent Document 3] EV Antonakou et al. Polym. Degrad. Stab., 2014, 110, 482-491 [Non-Patent Document 4] MN Siddiqui et al., Thermochim. Acta, 2019, 675, 69-76 [Non-Patent Document 5] DS Achilias et al., J. Appl. Polym. Sci., 2009, 114, 212-221 [Non-Patent Document 6] EC Vouvoudi et al., Front. Environ. Sci. Eng., 2017, 11, 9 [Non-Patent Document 7] T. Yoshioka et al., Polym. Degrad. Stab., 2009, 94, 1119-1124 [Non-Patent Document 8] T. Yoshioka et al., Ind. Eng. Chem. Res., 2014, 53, 4215-4223

[0019] It was therefore an object to provide, for the commercial implementation of pyrolysis, a process for pyrolysis of a material to be pyrolyzed, which preferably comprises at least one polycarbonate-containing compound(s) having oxygen-functionalized aromatic structural fragments, and a pyrolysis device which can be used in said process, which allows pyrolysis to be carried out at moderate temperatures and short residence times with improved selectivity, even when using relatively large amounts of material to be pyrolyzed, so that cleavage products which can be reused for the production of polycarbonate-containing materials are obtained in amounts preferably of more than 40% by weight, based on the total weight of polycarbonate-containing compounds in the material to be pyrolyzed used for the pyrolysis.

[0020] Thus, the present application provides a method for producing a method for producing a pharmaceutical composition comprising at least the following steps: (a) introducing into a reactor a material to be pyrolyzed comprising at least one polycarbonate-containing compound and a total amount of one or more phosphorus-containing organic compounds, said total amount relative to the total weight of the material to be pyrolyzed contributing at least 0.01% by weight of phosphorus having a formal oxidation state of +5, preferably at least 0.05% by weight of phosphorus having a formal oxidation state of +5, more preferably at least 0.1% by weight of phosphorus having a formal oxidation state of +5, and particularly preferably at least 0.5% by weight of phosphorus having a formal oxidation state of +5; (b) A step of decomposing the polycarbonate-containing compound introduced into the reactor in the step (a) at a temperature of 300°C to 700°C to obtain a gas-phase product as a pyrolysis product and a non-gas-phase pyrolysis residue, (i) during the decomposition, the amount of oxygen gas in the reactor is 0% by volume to 2.0% by volume relative to the total volume of gas present in the reactor; and (ii) discharging the pyrolysis product from the reactor during the decomposition; and (iii) discharging the pyrolysis residue from the reactor; (c) cooling the discharged pyrolysate to a temperature of less than 300° C. to obtain a pyrolysis product selected from a pyrolysate condensate, a pyrolysate resublimate, or a mixture thereof; (d) optionally post-treating the pyrolysis product; The present invention provides a process for pyrolyzing a polycarbonate-containing compound, comprising:

[0021] The term "material to be pyrolyzed" refers to the totality of the material introduced into the reactor for pyrolysis, where it undergoes heat treatment in the absence or presence of low amounts of oxygen gas. The material to be pyrolyzed is preferably in solid form prior to introduction into the reactor.

[0022] "Pyrolysate" is understood to mean the totality of the products formed by pyrolysis which are in the gas phase in the reactor (more particularly in the form of a gas and / or aerosol) under the conditions of step (b).

[0023] "Pyrolysis residue" is understood to mean the totality of the substances formed by pyrolysis and other residues of the material to be pyrolyzed that are not in the gas phase in the reactor under the conditions of step (b). Preferred is an embodiment of the process characterized in that the pyrolysis residue in the reactor is solid.

[0024] "Pyrolysis products" is understood to mean the totality of products from the pyrolysis which accumulate by condensation and / or resublimation when the pyrolysis product is cooled in step (c). The liquid pyrolysis products are also called pyrolysis oils.

[0025] Unless otherwise expressly defined in this context, a substance (e.g., material, material to be pyrolyzed, pyrolysate, pyrolysis product, pyrolysis residue) is "liquid" if it is in a liquid state at 20° C. and 1013 mbar. Unless otherwise expressly defined in this context, a substance (e.g., material, material to be pyrolyzed, pyrolysate, pyrolysis product, pyrolysis residue) is "solid" if it is in a solid state at 20° C. and 1013 mbar. Unless otherwise expressly defined in this context, a substance (e.g., material, material to be pyrolyzed, pyrolysate, pyrolysis product, pyrolysis residue) is "gaseous" if it exists as a gas at 20° C. and 1013 mbar.

[0026] A substance is "organic" if its chemical structure contains at least one covalent carbon-hydrogen bond.

[0027] In this application, the average molar masses specified for polymers or polymer components are always weight-average molar masses Mw, unless expressly stated otherwise, which can in principle be determined by gel permeation chromatography using a suitable RI detector to carry out the measurement against an external standard.

[0028] The term "polycarbonate-containing compound" refers to a homopolymer or copolymer obtained by polyreaction, in which at least one repeat unit is selected from at least one * -OC(=O)-O- * (In the formula, *represents the valence of the polymer main chain).

[0029] The "polymer having a structural unit derived from styrene" is a polymeric compound selected from homopolymers or copolymers obtained by polyreaction and having at least one structural unit derived from styrene as a repeating unit.

[0030] A "reactor" is a volume in which chemical conversion of material from the material to be pyrolyzed, e.g., thermal decomposition, takes place. In the case of thermal decomposition, this can be, for example, the volume of a heated vessel containing the material to be pyrolyzed.

[0031] According to the invention, it is advantageous to introduce the material to be pyrolyzed according to the process of the invention into a reactor, characterized in that it is selected from a continuous stirred tank reactor (CSTR), a fixed bed reactor, a fluidized bed reactor, a screw reactor, a screw conveyor reactor, an entrained-flow reactor, an entrainment-flow reactor, a rotating tube reactor, a fluidized bed reactor and a drum reactor. More particularly, suitable reactors are preferably those into which the material to be pyrolyzed can be continuously introduced, in particular selected from a rotating tube reactor, a continuous stirred tank reactor (CSTR), a fixed bed reactor (in particular with an internal heat exchanger, preferably with an internal heat exchanger tube (shaft reactor)), a screw reactor, a screw conveyor reactor, an entrainment reactor, a rotating tube reactor or a fluidized bed reactor. In one embodiment of the process, very particularly preferred reactors are selected from a screw reactor, a rotating oven or a fluidized bed. Further reactors preferred in the process and embodiments of the present invention are described in the pyrolysis apparatus embodiments and catalytic process embodiments of the present invention (see below).

[0032] According to the invention, the material to be pyrolyzed introduced into the reactor comprises at least one polycarbonate-containing compound and at least one phosphorus-containing organic compound. A suitable material to be pyrolyzed can be provided in various ways: the compounds may be present, for example, in the waste product material to be recycled from the beginning, the material being obtained, for example, as plastic waste, and added to the material to be pyrolyzed according to the invention to recover raw materials. For example, the waste product material to be recycled may comprise polycarbonate-containing compounds but not the phosphorus-containing organic compound, the phosphorus-containing organic compound being added to this material before it is added to the material to be pyrolyzed according to the invention to recover raw materials.

[0033] In one embodiment of the process according to the present invention, the material to be pyrolyzed contains the polycarbonate-containing compound in a total amount of 10.0% by weight to 80.0% by weight, more preferably 30.0% by weight to 70.0% by weight, based on the total weight of the material to be pyrolyzed.

[0034] It has been found to be advantageous that the polycarbonate-containing compound, preferably in a mixture with the phosphorus-containing organic compound, is present in the material to be pyrolyzed and is preferably introduced into the reactor in the form of solid particles, in particular in the form of a granular mixture. The granular mixture of the mixture is formed from loose solid particles of the mixture, these particles being composed of what are known as granules. A granule is a term that refers to powders (where the multiple granules are loose solid particles), dusts (where the multiple granules are loose solid particles), granules (where the loose solid particles are an agglomeration of several granules), and other granular components of granular mixtures. The flowability of a granular mixture relates to its ability to flow freely under its own weight from a flow test funnel with an outlet of 16.5 mm diameter.

[0035] For example, the corresponding solid particles can be obtained from recycled waste product materials containing the polycarbonate-containing compounds and the phosphorus-containing organic compounds by crushing or shredding the materials to recover raw materials, and the obtained solid particles can be added to the material to be pyrolyzed according to the present invention.

[0036] The solid particles, more particularly the loose solid particles of the granular mixture, have a median diameter x of 0.01 mm to 5 cm, preferably 0.1 mm to 5 cm. 50.3 It is preferable that the median particle size is X (volume average). 50.3 is determined by sieving or by using a Camsizer particle size analyzer manufactured by Retsch.

[0037] In general, the polycarbonate-containing compound can be, for example, a homopolymer, copolymer, comb polymer, block polymer, or mixtures thereof.

[0038] The polycarbonate-containing compound of this type contains at least 10 polycarbonate-containing compounds in addition to the polystyrene-containing compounds. * -OC(=O)-O- * (In the formula, * It is particularly preferred that at least one compound is present that contains the structural unit:

[0039] The polycarbonate-containing compounds suitable for the process of the present invention are preferably aromatic polycarbonates, polycarbonate copolymers and / or aromatic polyestercarbonates.They can be prepared by processes known from the literature or by processes known from the literature (for the preparation of aromatic polycarbonates, see, for example, Schnell, "Chemistry and Physics of Polycarbonates", Interscience Publishers, 1964, and also DE-A-1495626, DE-A-2232877, DE-A-2703376, DE-A-2714544, DE-A-3000610, DE-A-3832396; for the preparation of aromatic polyestercarbonates, see, for example, DE-A-3007934).

[0040] Thus, in accordance with the present invention, in a preferred embodiment of the present invention, the material to be pyrolyzed comprises at least one polycarbonate-containing compound having oxygen-functionalized aromatic structural fragments.

[0041] Aromatic polycarbonates that can be used as polycarbonate-containing compounds are produced, for example, by reacting aromatic compounds having at least two hydroxyl groups, especially diphenols, with carbonyl halides, preferably phosgene and / or aromatic dicarboxylic acid dihalides, preferably dihalides of benzenedicarboxylic acids, in an interfacial process, optionally using chain terminators, such as monophenols, and optionally using trifunctional or higher branching agents, such as triphenols or tetraphenols.Preparation via a melt polymerization process is also possible by reacting compounds having at least two hydroxyl groups, especially diphenols, with, for example, diphenyl carbonate.

[0042] According to the invention, it is possible to advantageously use such pyrolysates, in which the polycarbonate-containing compound is at least one compound obtainable by reacting at least (i) at least one aromatic compound having at least two hydroxyl groups, particularly preferably bisphenol A, with (ii) phosgene or diphenyl carbonate.

[0043] For the preparation of the polycarbonate-containing compounds, it is preferred to use at least one aromatic compound having at least two hydroxyl groups selected from the general formula (I): [ka] (In the formula, A is a single bond, C1-C5 alkylene, C2-C5 alkylidene, C5 or C6 cycloalkylidene, -O-, -SO-, -CO-, -S-, -SO2-, C6-C alkylene optionally condensed with a further aromatic ring containing a heteroatom. 12 arylene or a radical of formula (II) or formula (III), [ka] B is C1~C in either case. 12 alkyl, preferably methyl; halogen, preferably chlorine and / or bromine; x, in each occurrence, is independently 0, 1, or 2; p is 1 or 0; R 5 and R 6 is each X 1 and each independently represents hydrogen or C1-C6 alkyl, preferably hydrogen, methyl or ethyl; X 1 is carbon, 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 are both alkyl).

[0044] Preferred aromatic compounds having at least two hydroxyl groups are hydroquinone, resorcinol, dihydroxydiphenols, bis(hydroxyphenyl)-C1-C5 alkanes, bis(hydroxyphenyl)-C5 or -C6 cycloalkanes, bis(hydroxyphenyl)ethers, bis(hydroxyphenyl)sulfoxides, bis(hydroxyphenyl)ketones, bis(hydroxyphenyl)sulfones and α,α-bis(hydroxyphenyl)diisopropylbenzenes, and their ring-brominated and / or ring-chlorinated derivatives.

[0045] Particularly preferred aromatic compounds having at least two hydroxyl groups 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 also their dibrominated or dichlorinated derivatives 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.Particularly preferred is 2,2-bis(4-hydroxyphenyl)propane (bisphenol A).

[0046] The aromatic compounds having at least two hydroxyl groups can be used alone or in any desired mixture. The aromatic compounds having at least two hydroxyl groups can be known from the literature or obtained by methods known from the literature.

[0047] Examples of chain terminators suitable for the preparation of thermoplastic aromatic polycarbonates include phenol, p-chlorophenol, p-tert-butylphenol or 2,4,6-tribromophenol, and also 4-[2-(2,4,4-trimethylpentyl)]phenol, 4-(1,3-tetramethylbutyl)phenol according to DE-A-2 842 005 or mono- or dialkylphenols with a total of 8 to 20 carbon atoms in the alkyl substituents, such as 3,5-di-tert-butylphenol, p-isooctylphenol, p-tert-octylphenol, p-dodecylphenol and long-chain alkylphenols such as 2-(3,5-dimethylheptyl)phenol and 4-(3,5-dimethylheptyl)phenol. The amount of chain terminator used is usually 0.5 mol % to 10 mol %, based in each case on the total moles of the aromatic compound having at least two hydroxyl groups used.

[0048] In a preferred embodiment of the present invention, the thermoplastic aromatic polycarbonates that can be used preferably have an average molecular weight (weight average M measured by GPC (gel permeation chromatography) using polycarbonate standards based on bisphenol A) of 20,000 g / mol to 40,000 g / mol, more preferably 24,000 g / mol to 32,000 g / mol, particularly preferably 26,000 g / mol to 30,000 g / mol. w ).

[0049] The thermoplastic aromatic polycarbonates may be made branched in known manner, preferably by including 0.05 mol % to 2.0 mol % of a trifunctional or higher functional compound, e.g., one having three or more phenolic groups, based on the total amount of aromatic compounds having at least two hydroxyl groups used.

[0050] It is preferred to use linear polycarbonates, more preferably those based on bisphenol A.

[0051] Both homopolycarbonates and copolycarbonates are suitable. For the preparation of the copolycarbonates which can be preferably used according to the invention, it is also possible to use polydiorganosiloxanes having 1% to 25% by weight, preferably 2.5% to 25% by weight, of hydroxyaryloxy end groups, based on the total amount of aromatic compounds having at least two hydroxyl groups used. These are known (US Pat. No. 3,419,634) and can be prepared by processes known from the literature. Polydiorganosiloxane-containing copolycarbonates are also suitable, the preparation of which is described, for example, in DE-A-3,334,782.

[0052] The aromatic dicarboxylic acid dihalides for the production of aromatic polyester carbonates are preferably the diacid dichlorides of isophthalic acid, terephthalic acid, diphenyl ether 4,4'-dicarboxylic acid and naphthalene-2,6-dicarboxylic acid.

[0053] Particularly preferred is a mixture of the diacid dichloride of isophthalic acid and the diacid dichloride of terephthalic acid in a ratio of 1:20 to 20:1.

[0054] In the preparation of polyester carbonates, a carbonyl halide, preferably phosgene, is additionally used as a difunctional acid derivative.

[0055] Chain terminators useful for the production of aromatic polyester carbonates include, in addition to the monophenols already mentioned, their chlorocarbonates and C1-C 22 Acid chlorides of aromatic monocarboxylic acids, optionally substituted with alkyl or halogen atoms, and aliphatic C2-C 22 Monocarboxylic acid chlorides are included.

[0056] The amount of chain terminator is in each case between 0.1 mol % and 10 mol % relative to the moles of aromatic compounds having at least two hydroxyl groups in the case of phenolic chain terminators and relative to the moles of dicarboxylic acid dichlorides in the case of monocarboxylic acid chloride chain terminators.

[0057] One or more aromatic hydroxycarboxylic acids may also be used in the preparation of the aromatic polyester carbonates.

[0058] The aromatic polyestercarbonates can be linear or branched in known manner (see DE-A-2 940 024 and DE-A-3 007 934), although linear polyestercarbonates are preferred.

[0059] The branching agents used are, for example, trifunctional or polyfunctional carboxylic acid chlorides such as trimesyl trichloride, cyanuric trichloride, 3,3',4,4'-benzophenonetetracarboxylic acid tetrachloride, 1,4,5,8-naphthalenetetracarboxylic acid tetrachloride or pyromellitic acid tetrachloride in an amount of 0.01 mol % to 1.0 mol % (relative to the dicarboxylic acid dichloride used), or phloroglucinol, 4,6-dimethyl-2,4,6-tri(4-hydroxyphenyl)hept-2-ene, 4,6-dimethyl-2,4,6-tri(4-hydroxyphenyl)heptane, 1,3,5-tri(4-hydroxyphenyl)benzene, 1,3,5-tri(4-hydroxyphenyl)benzene, 1,4,5,8-naphthalenetetracarboxylic acid tetrachloride, 1,5,6-tri(4-hydroxyphenyl)benzene, 1,6,7-tri(4-hydroxyphenyl)benzene, 1,7,8-tri(4-hydroxyphenyl)benzene, 1,8,9-tri(4-hydroxyphenyl)benzene, 1,9,10 ... The branching agent may be a trifunctional or polyfunctional phenol such as 1,1-tri(4-hydroxyphenyl)ethane, tri(4-hydroxyphenyl)phenylmethane, 2,2-bis[4,4-bis(4-hydroxyphenyl)cyclohexyl]propane, 2,4-bis(4-hydroxyphenylisopropyl)phenol, tetra(4-hydroxyphenyl)methane, 2,6-bis(2-hydroxy-5-methylbenzyl)-4-methylphenol, 2-(4-hydroxyphenyl)-2-(2,4-dihydroxyphenyl)propane, tetra(4-[4-hydroxyphenylisopropyl]phenoxy)methane, 1,4-bis[4,4'-dihydroxytriphenyl)methyl]benzene, etc. The phenolic branching agent may be charged first together with the diphenol, and the acid chloride branching agent may be introduced together with the acid dichloride.

[0060] The proportion of carbonate structural units in thermoplastic aromatic polyester carbonates can be varied as desired.Preferably, the proportion of carbonate groups is up to 100 mol%, particularly up to 80 mol%, more preferably up to 50 mol%, based on the sum of ester groups and carbonate groups.Both the ester and carbonate parts of aromatic polyester carbonates can be present in the polycondensate in the form of blocks or in random distribution.

[0061] The aromatic polycarbonates and polyester carbonates can be used alone or in any desired mixture in said material to be pyrolyzed in the process according to the invention.

[0062] Generally, the pyrolysis product used according to the present invention comprises at least one phosphorus-containing organic compound in a certain total amount resulting in the introduction of phosphorus content, which results in an increase in the amount of aromatic compounds having exactly one hydroxyl group obtained in the pyrolysis product after pyrolysis, where the phosphorus-containing organic compound is selected from phosphorus-containing organic compounds in which phosphorus has a formal oxidation state of +5.

[0063] The phosphorus-containing organic compound that can be preferably used is selected from at least one compound of the group that includes organic phosphate esters.The phosphorus-containing organic compound is particularly preferably selected from at least one compound of the group that is formed by organic phosphate monoesters, organic phosphate diesters, organic phosphate triesters, and organic oligomeric phosphate esters.Therefore, it is also possible to use a mixture of two or more of these compounds.

[0064] For the purposes of the present invention, particularly preferred phosphorus-containing organic compounds are compounds of the general formula (IV): [ka] (In the formula, R 1 , R 2 , R 3 and R 4 are each independently an optionally halogenated C1-C8 alkyl, in each case an alkyl, preferably a C1-C4 alkyl and / or a C5 or C6 cycloalkyl optionally substituted with halogen, preferably chlorine or bromine, a C6-C 20 Aryl or C7-C 12 It is aralkyl, n is independently 0 or 1; q is 0 to 30; X is a polycyclic aromatic radical having 12 to 30 carbon atoms, which may be substituted with OH and may have up to 8 ether bonds, or a linear or branched aliphatic radical having 2 to 30 carbon atoms.

[0065] R in formula (IV) 1 , R 2 , R 3 and R 4 are preferably each independently C1 to C4 alkyl, phenyl, naphthyl, or phenyl-C1 alkyl to phenyl-C4 alkyl. 1 , R 2 , R 3 and R 4 may be substituted with halogen and / or alkyl groups, preferably chlorine, bromine and / or C1-C4 alkyl. Particularly preferred aryl radicals are cresyl, phenyl, xylenyl, propylphenyl or butylphenyl, and also the corresponding brominated and chlorinated derivatives thereof.

[0066] X in formula (IV) is preferably a polycyclic aromatic radical having 12 to 30 carbon atoms, which is preferably derived from an aromatic compound having at least two hydroxyl groups of general formula (I).

[0067] In formula (IV), n can independently be 0 or 1, and n is preferably 1.

[0068] q has an integer value of 0 to 30, preferably 0 to 20, more preferably 0 to 10, or in the case of a mixture, has an average value of 0.8 to 5.0, preferably 1.0 to 3.0, more preferably 1.05 to 2.00, particularly preferably 1.08 to 1.60.

[0069] X in formula (IV) is particularly preferably [ka] or its chlorinated or brominated derivatives, in particular X is derived from bisphenol A or diphenylphenol. More preferably, X is derived from bisphenol A.

[0070] Phosphorus compounds of formula (IV) are in particular tributyl phosphate, triphenyl phosphate, tricresyl phosphate, diphenyl cresyl phosphate, diphenyl octyl phosphate, diphenyl 2-ethylcresyl phosphate, tri(isopropylphenyl) phosphate and oligophosphates linked with bisphenol A. It is particularly preferable to use oligomeric phosphate esters of formula (IV) derived from bisphenol A.

[0071] Most preferably, the phosphorus-containing organic compound used is an oligophosphate based on bisphenol A as shown in formula (IVa). [ka]

[0072] The above-mentioned phosphorus-containing organic compounds are known (see, for example, EP-A-0 363 608, EP-A-0 640 655) or can be prepared similarly by known methods (see, for example, Ullmann's Encyclopedia of Industrial Chemistry, vol. 18, p. 301ff, 1979; Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], vol. 12 / 1, p. 43; Beilstein vol. 6, p. 177).

[0073] As phosphorus-containing organic compounds suitable according to the invention, for example, mixtures of organophosphates having different chemical structures and / or organophosphates having the same chemical structure but different molecular weights can also be used.

[0074] When using oligomeric phosphate esters as phosphorus-containing organic compounds, it is preferable to use a mixture of oligomeric phosphate esters having the same structure but different chain lengths. Here, the q values ​​shown in formula (IV) and formula (IVa) are average q values. The average q value is determined by determining the composition (molecular weight distribution) of phosphorus compounds in a mixture of acetonitrile and water (50:50) at 40°C using high performance liquid chromatography (HPLC) and calculating the average value of q therefrom.

[0075] A particularly preferred embodiment of the material to be pyrolyzed comprises a phosphorus-containing organic compound in which phosphorus is in the formal oxidation state of +5, in particular the preferred phosphorus-containing organic compounds mentioned above (in particular the phosphorus-containing organic compounds of formula (IV)), in a total amount of 0.1% by weight to 20.0% by weight, more preferably 0.5% by weight to 15.0% by weight, most preferably 2.0% by weight to 12.0% by weight, based on the total weight of the material to be pyrolyzed.

[0076] A further embodiment of the material to be pyrolyzed which is particularly preferably used in the above-mentioned process is characterized in that in step (a) the ratio of the total weight of all phosphorus-containing organic compounds present in the material to be pyrolyzed in which phosphorus is in the formal oxidation state of +5 to the total weight of all polycarbonate-containing compounds present in the material to be pyrolyzed is in the range of a weight ratio of 1:1000 to 1:5, more preferably 1:200 to 1:7, most preferably 1:50 to 1:10.

[0077] The material to be pyrolyzed preferably contains, in addition to at least one polycarbonate-containing compound and at least one phosphorus-containing organic compound, at least one polymer having structural units derived from styrene, such as polymers in which at least one repeat unit is derived from styrene (in particular styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, etc.) optionally substituted with an aromatic ring.

[0078] In one embodiment of the process according to the invention, at least 10 compounds of the formula: * -CR 1 Ph-CH2-* (In the formula, * represents the valence of the repeating unit of the polymer main chain, R 1 It is possible to use in the material to be pyrolyzed polymers of this type having structural units derived from styrene with repeating units of the formula: R is a hydrogen atom or a methyl group, and Ph is a phenyl group optionally substituted with at least one group selected from C1-C4 alkyl groups and halogen atoms, in particular chlorine. In addition to at least one polycarbonate-containing compound, the material to be pyrolyzed particularly preferably contains styrene (R 1 = H, Ph = phenyl), α-methylstyrene (R 1 = methyl, Ph = phenyl), p-methylstyrene (R 1 = H, Ph = 4-methylphenyl), p-chlorostyrene (R 1 =H, Ph=4-chlorophenyl), or mixtures thereof.

[0079] The material to be pyrolyzed that can be preferably used according to the present invention additionally contains, as a polymer having structural units derived from styrene, at least one polymer selected from a rubber-modified graft polymer (B1) having structural units derived from styrene and a rubber-free vinyl (co)polymer (B2) having structural units derived from styrene, or a mixture of two or more of such polymers.

[0080] The rubber-modified graft polymer (B1) preferably used is B.1.1 5% to 95% by weight, preferably 15% to 92% by weight, in particular 25% to 60% by weight, of vinyl aromatic compounds and / or ring-substituted vinyl aromatic compounds (styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, etc.), based on component B.1, B.1.2 95% to 5% by weight, preferably 85% to 8% by weight, in particular 75% to 40% by weight, based on component B.1, of one or more rubbery graft bases, preferably having a glass transition temperature of less than 10° C., more preferably less than 0° C., particularly preferably less than −20° C., include.

[0081] The glass transition temperature was measured by differential scanning calorimetry (DSC) according to the DIN EN61006 standard at a heating rate of 10 K / min, T g is defined as the midpoint temperature (tangent method).

[0082] The graft base B.1.2 usually has a median particle size (d 50 ) Median particle size d 50 are the diameters at which 50% by weight of the particles lie, respectively. Median particle size d 50 can be determined by ultracentrifugation measurements (W. Scholtan, H. Lange, Kolloid, Z. und Z. Polymere 250 (1972), 782-1796).

[0083] Monomer B.1.1 is B.1.1.1 50 to 99 parts by weight, preferably 60 to 80 parts by weight, in particular 70 to 80 parts by weight, of vinyl aromatic compounds and / or ring-substituted vinyl aromatic compounds, in particular selected from styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene or mixtures thereof, based on B.1.1, B.1.1.2 Based on B.1.1, 1 to 50 parts by weight, preferably 20 to 40 parts by weight, particularly 20 to 30 parts by weight of vinyl cyanide (unsaturated nitrile such as acrylonitrile and methacrylonitrile) and / or C1 to C8 alkyl (meth)acrylate such as methyl methacrylate, n-butyl acrylate, tert-butyl acrylate, and / or unsaturated carboxylic acid derivatives (anhydrides, imides, etc.), for example maleic anhydride and N-phenylmaleimide, It is preferred that the mixture is

[0084] Preferred monomers B.1.1.1 are selected from at least one of the monomers styrene and α-methylstyrene, and preferred monomers B.1.1.2 are selected from at least one of the monomers acrylonitrile, maleic anhydride and methyl methacrylate. Particularly preferred monomers are styrene as B.1.1.1 and acrylonitrile as B.1.1.2.

[0085] Examples of suitable graft bases B.1.2 for the graft polymers B.1 are diene rubbers, EP(D)M rubbers, i.e. rubbers based on ethylene / propylene and optionally dienes, acrylate rubbers, polyurethane rubbers, silicone rubbers, chloroprene rubbers and ethylene / vinyl acetate rubbers, and also silicone / acrylate hybrid rubbers.

[0086] Preferred graft bases B.1.2 are diene rubbers or mixtures of diene rubbers, for example based on butadiene and isoprene, or copolymers of diene rubbers or mixtures of these with further copolymerizable monomers (for example according to B.1.1.1 and B.1.1.2).

[0087] Particularly preferred as graft base B.1.2 is pure polybutadiene rubber.

[0088] Particularly preferred as polymer B1 are polymers selected from, for example, acrylonitrile-butadiene-styrene copolymers (also called ABS polymers) or methacrylate-butadiene-styrene copolymers (also called MBS polymers), as described, for example, in DE-A-2 035 390 (=US Pat. No. 3,644,574) or DE-A-2 248 242 (=GB-A-1 409 275) or Ullmann's Encyclopedia of Industrial Chemistry, Vol. 19 (1980), p. 280 ff.

[0089] The graft copolymers B.1 are prepared by free-radical polymerization, for example emulsion, suspension, solution or bulk polymerization, preferably emulsion or bulk polymerization.

[0090] The gel content of the graft base B.1.2 is at least 30% by weight, preferably at least 40% by weight and in particular at least 60% by weight, measured as the insoluble fraction in toluene, in each case relative to B.1.2.

[0091] The gel content of the graft base B.1.2 is determined in appropriate solvents at 25° C. as the content that is insoluble in these solvents (M. Hoffmann, H. Kroemer, R. Kuhn, Polymeranalytik I und II [Polymer analysis I and II], Georg Thieme-Verlag, Stuttgart 1977).

[0092] Particularly suitable graft rubbers include ABS polymers prepared by redox initiation using an initiator system comprised of an organic hydroperoxide and ascorbic acid in accordance with US Pat. No. 4,937,285.

[0093] Since it is known that the grafting monomers are not always completely grafted onto the graft base in the grafting reaction, according to the invention the graft polymers B.1 are understood to also include the products resulting from the (co)polymerization of the grafting monomers in the presence of the graft base and obtained during after-treatment. These products may therefore also include free (co)polymers of the grafting monomers, i.e. (co)polymers that are not chemically bound to the rubber.

[0094] Monomers having two or more polymerizable double bonds may be copolymerized for the purpose of crosslinking. Preferred examples of crosslinking monomers include esters of unsaturated monocarboxylic acids having 3 to 8 carbon atoms, such as ethylene glycol dimethacrylate and allyl methacrylate, with unsaturated monohydric alcohols having 3 to 12 carbon atoms or saturated polyols having 2 to 20 carbon atoms and 2 to 4 OH groups; polyunsaturated heterocyclic compounds such as trivinyl and triallyl cyanurate; polyfunctional vinyl compounds such as divinylbenzene and trivinylbenzene, as well as triallyl phosphate and diallyl phthalate. Preferred crosslinking monomers are allyl methacrylate, ethylene glycol dimethacrylate, diallyl phthalate, and heterocyclic compounds having at least three ethylenically unsaturated groups. Particularly preferred crosslinking monomers are the cyclic monomers triallyl cyanurate, triallyl isocyanurate, triacryloylhexahydro-s-triazine, and triallyl benzene. The amount of crosslinking monomer is preferably 0.02% to 5% by weight, in particular 0.05% to 2% by weight, based on the graft base B.1.2. In the case of cyclic crosslinking monomers having at least three ethylenically unsaturated groups, it is advantageous to limit the amount to less than 1% by weight of the graft base B.1.2.

[0095] Preferred "other" polymerizable ethylenically unsaturated monomers which can optionally be used together with the acrylic esters for the preparation of the graft base B.1.2 are, for example, acrylonitrile, styrene, α-methylstyrene, acrylamide, vinyl C1-C6 alkyl ethers, methyl methacrylate and butadiene. Preferred acrylate rubbers as graft base B.1.2 are emulsion polymers having a gel content of at least 60% by weight.

[0096] Other suitable graft bases according to B.1.2 are silicone rubbers which have active grafting sites, as described in DE-A-37 04 657, DE-A-37 04 655, DE-A-36 31 540 and DE-A-36 31 539.

[0097] The rubber-free vinyl (co)polymers according to component B.2 are preferably rubber-free homopolymers and / or copolymers of at least one monomer from the group comprising vinyl aromatics, vinyl cyanides (unsaturated nitriles), C1-C8 alkyl (meth)acrylates, unsaturated carboxylic acids and unsaturated carboxylic acid derivatives, such as anhydrides and imides.

[0098] B.2.1 50% to 99% by weight, preferably 60% to 80% by weight and in particular 70% to 80% by weight, of at least one monomer selected from the group comprising vinyl aromatic compounds, such as styrene, α-methylstyrene, ring-substituted vinyl aromatic compounds, such as p-methylstyrene, p-chlorostyrene (and optionally additionally C1-C8 alkyl (meth)acrylates, such as methyl methacrylate, n-butyl acrylate and tert-butyl acrylate), in each case relative to the total weight of the (co)polymer B.2, B.2.2 from 1% to 50% by weight, preferably from 20% to 40% by weight and in particular from 20% to 30% by weight of at least one monomer selected from the group comprising vinyl cyanides, unsaturated nitriles such as acrylonitrile and methacrylonitrile, C1-C8 alkyl (meth)acrylates, such as methyl methacrylate, n-butyl acrylate and tert-butyl acrylate, unsaturated carboxylic acids and unsaturated carboxylic acid derivatives, such as maleic anhydride and N-phenylmaleimide, in each case relative to the total weight of the (co)polymer B.2, Particularly preferred are (co)polymers B.2 obtained from

[0099] These (co)polymers B.2 are resinous, thermoplastic and rubber-free. It is particularly preferred that said materials comprise at least B.2.1 styrene and B.2.2 acrylonitrile.

[0100] (Co)polymers of this kind B.2 are known and can be prepared by free-radical polymerization, in particular by emulsion, suspension, solution or bulk polymerization. The (co)polymers preferably have average molecular weights M in the range of 15000 g / mol to 250000 g / mol, preferably 80000 g / mol to 150000 g / mol. w (weight average determined by GPC using polystyrene as standard).

[0101] Particularly preferably, the material to be pyrolyzed used in the present process additionally comprises at least one polymer having structural units derived from styrene selected from at least one representative of the group formed by polystyrene, polybutadiene rubber modified polystyrene (HIPS), styrene-acrylonitrile copolymer (SAN), acrylonitrile-butadiene-styrene terpolymer (ABS), methyl methacrylate-butadiene-styrene terpolymer (MBS) and butyl acrylate-styrene-acrylonitrile terpolymer (ASA).

[0102] In addition to at least one polycarbonate-containing compound and at least one phosphorus-containing organic compound in which phosphorus is in the formal oxidation state of +5, the material to be pyrolyzed may additionally contain at least one polymer additive different from the above-mentioned compounds selected from further flame retardants, anti-drip agents, flame retardant synergists, smoke suppressants, lubricants and release agents, nucleating agents, antistatic agents, conductive additives, stabilizers (e.g. hydrolysis, heat aging and UV stabilizers, and also transesterification inhibitors), flow promoters, phase compatibilizers, further polymeric components other than component A and component B (e.g. functional compounding materials), fillers and reinforcing agents, and dyes and pigments.

[0103] In a preferred embodiment, the material includes at least one such additional polymer additive selected from the group consisting of lubricants and mold release agents, stabilizers (e.g., at least one stabilizer selected from sterically hindered phenols, sulfur-based co-stabilizers, or mixtures thereof), flow promoters, phase compatibilizers, additional polymeric components, dyes, and pigments.

[0104] In a preferred embodiment, the composition includes pentaerythritol tetrastearate as a mold release agent.

[0105] The metering and handling of the material to be pyrolyzed in the pyrolysis of the process of the invention can be simplified by the fact that the material to be pyrolyzed in step (a) also contains, in addition to the above-mentioned compound, at least one filler.The above-mentioned filler is preferably not catalytic to the thermal decomposition of polycarbonate during pyrolysis.It is therefore particularly preferred that the filler is at least one metal oxide, preferably selected from SiO2, which is not catalytically active to the thermal decomposition of polycarbonate during pyrolysis.

[0106] The polycarbonate material is preferably mixed with a filler, for example sand, to make the continuous process regime of the process according to the invention simpler. In particular, clogging of said material in the reactor and in the feed from the metering device to the reactor is avoided. In one embodiment, the filler and said material are fed to the material to be pyrolyzed as a mixture in which the volume ratio of filler to said material is at least 0.1:1 to 10:1.

[0107] A catalyst different from the phosphorus-containing organic compound may be additionally used to make the pyrolysis process even more selective and efficient. In one embodiment of the process according to the invention, a more effective and more selective decomposition is obtained if the material to be pyrolyzed introduced in step (a) contains, in addition to the compound, at least one catalyst that affects the decomposition reaction of the polycarbonate-containing compound. A suitable catalyst can lower the pyrolysis temperature, reduce the product spectrum to the desired products, and optionally minimize carbonization. For an efficient process, inexpensive catalysts are preferred. For example, naturally occurring materials that can be optionally ion-exchanged by a simple ion-exchange process, such as inorganic salts, refractory oxides, minerals and industrial stones, can be catalysts since they do not require extensive synthesis. They are relatively inexpensive because they are readily available. On the other hand, synthetic catalysts such as zeolites (e.g., ZSM-5, A, X, Y, etc. types) are examples of catalysts that, although effective, are not inexpensive because they need to be specially prepared.

[0108] In addition to its catalytic function, the catalyst can also facilitate the metering and processing of the material to be pyrolyzed during pyrolysis. The use of the catalyst can reduce the amount of filler used in this case. In one embodiment, the total amount of the filler and catalyst relative to the amount of the polycarbonate-containing compound is supplied to the material to be pyrolyzed as a mixture with a volume ratio of at least 0.1:1 to 10:1.

[0109] In the pyrolysis reaction, at least one catalyst is preferably selected from the group formed by alkaline inorganic materials, more preferably from the group comprising naturally occurring materials as defined above. These inorganic materials can be refractory oxides. Refractory oxides are metal oxides that are stable at high temperatures between 300°C and 700°C. Such oxides that function as catalysts include oxides of aluminum, magnesium, zirconium, titanium, chromium, zinc, tin and other metals, or combinations of aluminum oxide with magnesium oxide and / or calcium oxide. Crystalline inorganic materials include aluminosilicates, aluminum silicon phosphates, silicalites, spinels, and also natural zeolites and clays. Particularly suitable as said catalyst are therefore at least one compound from the group formed by inorganic salts, minerals, metal oxides, mixed oxides, clays and zeolites.

[0110] Although both homogeneous and heterogeneous catalysts can be used, a particularly preferred embodiment of the process according to the invention is one in which the catalyst is in the form of a heterogeneous catalyst. It has been found to be advantageous to introduce the catalyst into the reactor, preferably in the form of solid particles, in particular in the form of a granular mixture. The optionally used heterogeneous catalyst has a median diameter X 1 , which is the median particle size of its solid particles, more particularly of the loose solid particles of its granular mixture. 50.3 It is particularly preferable that the median particle size X (volume average) is 0.01 mm to 5 cm, and preferably 0.1 mm to 5 cm. 50.3 is determined by sieving or by using a Camsizer particle size analyzer manufactured by Retsch.

[0111] When using heterogeneous catalysts, it has been found to be advantageous for the catalyst particles to have a particle size smaller than or equal to that of the particles of the material comprising said compound to be pyrolyzed, and therefore it is preferred that the median particle size of the catalyst present in the material to be pyrolyzed corresponds at most to the median particle size of the material comprising said compound present in said material.

[0112] As the catalyst, the material to be pyrolyzed can contain at least one basic catalyst or at least one acid catalyst or a mixture thereof. In the case of solid basic catalysts, the number and strength of basic centers in the catalyst can be determined by Fourier transform infrared spectroscopy and temperature programmed desorption of CO2 (TPD-CO2), or in the case of acid catalysts, by standard titration methods.

[0113] If a catalyst is added, it may be mixed with the filler, coated on the filler, or used in place of the filler.

[0114] When catalysts are used, they tend to result in deposits of carbonized material and other carbon residues. Therefore, when catalysts are used, it is preferable to use a reactor in which the catalyst can be easily and preferably continuously discharged and regenerated. Thus, rather than using a fixed bed reactor, it is preferable to use a continuous stirred tank reactor (CSTR), moving bed, screw reactor, screw conveyor reactor, spout reactor, rotating cone reactor or fluidized bed reactor.

[0115] Deactivated catalyst (e.g. deactivated by carbonization) is present in the pyrolysis residue, which can be fed to a regenerator after the pyrolysis residue is discharged from the reactor and, after regeneration, introduced into the pyrolysis reactor in addition to the material to be pyrolyzed in step (b). Most preferred are reactors that allow short contact times, intensive mixing of the catalyst with the components in the feed stream and continuous recycling of the regenerated catalyst to the pyrolysis zone. This is the case for screw reactors, rotary ovens or fluidized beds, so these reactors are particularly preferred.

[0116] The material to be pyrolyzed introduced into the reactor in step (a) is at least partially decomposed according to step (b) to form a pyrolysis product and a pyrolysis residue.

[0117] After being introduced into the reactor, the material to be pyrolyzed is heated to a temperature in the range of 300° C. to 700° C. A particularly successful improvement of the results of the process of the invention can be achieved in one embodiment by heating the introduced material to be pyrolyzed to 300° C. to 700° C. and, once this target temperature has been reached, by setting the residence time of the correspondingly heated material to be pyrolyzed until the discharge time of the pyrolysis residue obtained from said material to be pyrolyzed to be between 1 second and 2 hours, preferably between 2 minutes and 60 minutes. During this time, the temperature and content of oxygen gas in the reactor are the values ​​specified in step (b).

[0118] If the material to be pyrolyzed used contains a catalyst, this catalyst is present in the loaded pyrolysis residue. In a further embodiment of the process, the above-mentioned discharged pyrolysis residue is therefore fed to a step for regenerating the catalyst contained therein.

[0119] Independently of this, good results can be achieved by ensuring that the pyrolysate is discharged from the reactor in step (b) by a gas flow passing through the reactor or by suction, and more preferably by ensuring that the residence time of the pyrolysate between the introduction of the compound introduced into the reactor in step (a) and the discharge of the pyrolysate is 0.1 seconds to 10 seconds, preferably 0.5 seconds to 5 seconds, more preferably 0.5 seconds to 2 seconds.

[0120] If a gas stream is passed through the reactor for this purpose, then as gas for this gas stream an inert gas, preferably selected from nitrogen, argon, CO2, NO or mixtures thereof, is particularly suitable.

[0121] When the pyrolysis product is discharged using a gas flow, the flow rate of the gas flow in the reactor as the superficial velocity is preferably in the range of 0.01 m / s to 20 m / s according to the present invention. When a fixed bed reactor is selected as the reactor, the flow rate of the gas flow in the reactor as the superficial velocity is preferably in the range of 0.03 m / s to 1 m / s according to the present invention. When a fluidized bed reactor is selected as the reactor, the flow rate of the gas flow in the reactor as the superficial velocity is preferably in the range of 0.5 m / s to 2 m / s according to the present invention. When a jet reactor is selected as the reactor, the flow rate of the gas flow in the reactor as the superficial velocity is preferably in the range of 5 m / s to 20 m / s according to the present invention.

[0122] As the conditions of the present invention for the decomposition in the pyrolysis in step (b), the temperature in the reactor is 300°C to 700°C, and the amount of oxygen gas in the reactor is 0% by volume to 2.0% by volume with respect to the total volume of gas present in the reactor.

[0123] According to the invention, this amount of oxygen gas is established by filling the reactor, loaded with the material to be pyrolyzed, with an inert gas, more particularly nitrogen, argon, CO2, NO or a mixture thereof. The inert gas can additionally be mixed with a reactive gas other than oxygen gas, in particular a gas selected from methane, gaseous H2O, hydrogen gas or a mixture thereof.

[0124] In order to minimize the ingress of oxygen gas due to the introduction of the material to be pyrolyzed into the reactor, oxygen gas can be removed from the material to be pyrolyzed before the material to be pyrolyzed is introduced in step (a), for example, in a storage vessel upstream of the reactor, for example, by stripping the oxygen gas with a stripping gas. For example, an inert gas, more particularly nitrogen, argon, CO2, NO, or a mixture thereof, can be passed as a stripping gas from the top or bottom of the storage vessel (preferably from the top) through a frit into the vessel and then through the material to be pyrolyzed to drive out the oxygen gas.

[0125] In a preferred embodiment of the process according to the invention, the temperature in step (b) is between 350°C and 650°C, preferably between 400°C and 650°C, particularly preferably between 420°C and 600°C and very particularly preferably between 450°C and 580°C.

[0126] In a further preferred embodiment of the process according to the invention, the amount of oxygen gas in the reactor in step (b) is in each case less than or equal to 0.5% by volume, preferably less than or equal to 0.1% by volume, relative to the total volume of gas present in the reactor.

[0127] In a very preferred embodiment of the process according to the invention, firstly, the temperature in step (b) is between 350°C and 650°C, preferably between 400°C and 650°C, particularly preferably between 420°C and 600°C and very particularly preferably between 450°C and 580°C, and secondly, the amount of oxygen gas in the reactor is in each case less than or equal to 0.5% by volume, preferably less than or equal to 0.1% by volume, relative to the total volume of gas present in the reactor.

[0128] A preferred embodiment of the process provides a continuous process regime. To this end, in the context of a continuous process regime, at least steps (a) and (b) are carried out simultaneously.

[0129] The pyrolysis product obtained according to step (c) can be worked up using standard separation methods to obtain at least one aromatic compound having one hydroxyl substituent, preferably phenol. As a standard procedure, the aromatic compound having one hydroxyl substituent, in particular phenol, can be separated by distillation.

[0130] The process of the invention can be carried out using a suitably configured pyrolysis device, for example a pyrolysis device for producing pyrolysis products from a material to be pyrolyzed, comprising at least one metering device for feeding the material to be pyrolyzed, at least one heatable reactor for pyrolysis and at least one pyrolysis product collector, The heatable reactor for pyrolysis comprises at least one heating unit that can be used to control the temperature in the reactor at temperatures between 300 ° C and 700 ° C, and also at least one inlet for the material to be pyrolyzed and at least one separate outlet for the pyrolysis product, The metering device and the heatable reactor for pyrolysis are arranged and configured relative to each other such that the metering device is connected to an inlet for the material to be pyrolyzed of the heatable reactor for pyrolysis via at least one supply line; the heatable reactor for pyrolysis and the pyrolysis product collector are in fluid communication with each other so that the pyrolysis product, preferably gaseous, can be discharged from the pyrolysis product outlet and the discharged pyrolysis product can be introduced into the pyrolysis product collector, At least one pyrolysis product collector can be used to reduce the temperature of the pyrolysis product discharged from the reactor to less than 300°C to form a pyrolysis product selected from a pyrolysis product condensate, a pyrolysis product resublimation product, or a mixture thereof, in the collector, and is provided with at least one cooling device temperature-controlled to a temperature of less than 300°C, and at least one container for collecting and discharging the pyrolysis product obtained by cooling; A pyrolysis apparatus, characterized in that at least one metering device for supplying material to be pyrolyzed, at least one heatable reactor for pyrolysis, and at least one pyrolysis product collector are arranged and configured relative to each other so that they can operate simultaneously.

[0131] The heating unit used in the heatable reactor can be, for example, a heating element, such as a heating coil or a heating plate, or a device that heats a gas stream and introduces the heated gas stream into the reactor.

[0132] In a preferred embodiment, the reactor additionally comprises at least one connection to a gas source, through which a gas flow, preferably with a superficial flow rate in the reactor of 0.01 m / s to 20 m / s, flows through the reactor via a regulator, for example a valve, to a pyrolysis product collector. When a fixed bed reactor is selected as the reactor, it is preferred according to the invention that the superficial flow rate of the gas flow in the reactor is in the range of 0.03 m / s to 1 m / s. When a fluidized bed reactor is selected as the reactor, it is preferred according to the invention that the superficial flow rate of the gas flow in the reactor is in the range of 0.5 m / s to 2 m / s. When a jet reactor is selected as the reactor, it is preferred according to the invention that the superficial flow rate of the gas flow in the reactor is in the range of 5 m / s to 20 m / s.

[0133] The gas stream from the gas source may be heated, for example by a heating unit, before being introduced into the reactor as described above.

[0134] The pyrolysis product collector of the device according to the invention is preferably equipped with a cooling device which can be used to reduce the temperature of the pyrolysis product discharged from the reactor in said collector to below 50° C., more preferably below 30° C., to form pyrolysis products. Cooling units operating according to the heat exchanger principle are particularly suitable for this.

[0135] According to the present invention, "fluid communication" is understood to mean a piece of equipment that connects parts of a system with each other and through which a substance, which may be in any state of matter, can be transported from one plant component to the next, for example a supply line in the form of a pipe.

[0136] The present invention further provides the use of the pyrolysis apparatus described above for recovering at least one organic aromatic compound having exactly one hydroxyl group by pyrolysis of said polycarbonate-containing compound in the presence of at least one phosphorus-containing organic compound.

[0137] In a preferred embodiment of said use, the pyrolysis unit is used for the recovery of phenol which is used to synthesize aromatic compounds having at least two hydroxyl groups in the production of polycarbonate-containing compounds.

[0138] The process according to the invention and the device usable therefor contribute to achieving the above-mentioned object, and in step (c) of the process, in each case relative to the total weight of the composition: (i) at least one aromatic compound having at least two hydroxyl groups, preferably bisphenol A, in a total amount of 0% to 10% by weight; (ii) at least one aromatic compound having exactly one hydroxyl group, preferably phenol, in a total amount of more than 12% by weight; (iii) optionally further ingredients; A composition comprising at least the following is provided as a pyrolysis product.

[0139] It is preferred that the composition contains a small amount of a high boiling point component. Thus, a preferred embodiment of the above-mentioned composition additionally contains at least one organic compound not containing hydroxyl groups, having a boiling point at 1013 mbar of at least 300° C., in a total amount of 0.5% to 10.0% by weight.

[0140] In a further embodiment of the composition, it contains at least one aromatic compound having at least one vinyl substituent, preferably styrene or α-methylstyrene, in a total amount of more than 1.5 wt.%.

[0141] In summary, the following aspects 1 to 25 of the present invention are considered as further embodiments, although they are not intended to be limiting.

[0142] 1. At least the following steps: (a) introducing into a reactor a material to be pyrolyzed comprising at least a polycarbonate-containing compound and a total amount of phosphorus-containing organic compounds, said total amount relative to the total weight of the material to be pyrolyzed contributing at least 0.01% by weight of phosphorus having a formal oxidation state of +5, preferably at least 0.05% by weight of phosphorus having a formal oxidation state of +5, more preferably at least 0.1% by weight of phosphorus having a formal oxidation state of +5, and particularly preferably at least 0.5% by weight of phosphorus; (b) a step of decomposing at least the polycarbonate-containing compound introduced into the reactor in the step (a) at a temperature of 300°C to 700°C to obtain a gas-phase product as a pyrolysis product and a non-gas-phase pyrolysis residue, (i) during the decomposition, the amount of oxygen gas in the reactor is 2.0% by volume or less based on the total volume of gas present in the reactor; and (ii) discharging pyrolysis products from the reactor during the decomposition; and (iii) discharging the pyrolysis residue from the reactor; (c) cooling the discharged pyrolysate to a temperature of less than 300° C. to obtain a pyrolysis product selected from a pyrolysate condensate, a pyrolysate resublimate, or a mixture thereof; (d) optionally post-treating the pyrolysis product; 1. A process for pyrolyzing a polycarbonate-containing compound, comprising:

[0143] 2. The process according to embodiment 1, characterized in that the temperature in step (b) is between 350°C and 650°C, preferably between 400°C and 650°C, particularly preferably between 420°C and 600°C, very particularly preferably between 450°C and 580°C.

[0144] 3. A process according to any one of the above aspects, characterized in that the introduced material to be pyrolyzed is heated to 300°C to 700°C, and, once this target temperature is reached, the residence time of the correspondingly heated material to be pyrolyzed until the discharge time of the pyrolysis residue resulting from said material to be pyrolyzed is 1 second to 2 hours, preferably 2 minutes to 60 minutes.

[0145] 4. A process according to any one of the above aspects, characterized in that the discharge of the pyrolysis product from the reactor is ensured by a gas flow passing through the reactor or by suction and preferably by a residence time of the pyrolysis product, as the time between the introduction of the material introduced into the reactor in step (a) and the discharge of the pyrolysis product obtained, of between 0.1 s and 10 s, preferably between 0.5 s and 5 s, more preferably between 0.5 s and 2 s.

[0146] 5. The process according to any one of the above aspects, characterized in that the discharge of the pyrolysis products from the reactor is ensured by a gas flow passing through the reactor, the flow rate of the gas flow in the reactor being in the range of 0.01 m / s to 20 m / s as superficial velocity.

[0147] 6. The process according to any one of the above embodiments, characterized in that at least steps (a) and (b) are carried out simultaneously in the context of a continuous process regime.

[0148] 7. The process according to any one of the previous aspects, characterized in that the amount of oxygen gas in the reactor in step (b) is less than or equal to 0.5% by volume, preferably less than or equal to 0.1% by volume, relative to the total volume of gas present in the reactor in each case.

[0149] 8. A process according to any one of the previous aspects, characterized in that the reactor charged with the material to be pyrolyzed is filled with an inert gas, in particular nitrogen, argon, CO2, NO or mixtures thereof.

[0150] 9. The polycarbonate-containing compound contains at least 10 * -OC(=O)-O- * (In the formula, * represents the valence of the polymer backbone).

[0151] 10. The process of any one of the preceding aspects, wherein the polycarbonate-containing compound is at least one compound having an oxygen-functionalized aromatic structural fragment.

[0152] 11. The process according to any one of the above aspects, characterized in that the polycarbonate-containing compound is at least one compound obtainable by reacting at least one aromatic compound having at least two hydroxyl groups, preferably bisphenol A, with (ii) phosgene or diphenyl carbonate.

[0153] 12. The process according to any one of the preceding aspects, characterized in that the phosphorus-containing organic compound is selected from at least one compound of the group comprising organic phosphates.

[0154] 13. The process according to any one of the preceding aspects, characterized in that the phosphorus-containing organic compound is selected from at least one compound of the group formed by organic phosphate monoesters, organic phosphate diesters, organic phosphate triesters, and organic oligomeric phosphate esters.

[0155] 14. The phosphorus-containing organic compound comprises at least one compound of general formula (IV): [ka] (In the formula, R 1 , R 2 , R 3 and R 4 are each independently an optionally halogenated C1 to C8 alkyl, a C5 or C6 cycloalkyl optionally substituted with alkyl, preferably C1 to C4 alkyl and / or halogen, preferably chlorine or bromine, a C6 to C7 alkyl optionally substituted with alkyl, preferably C1 to C4 alkyl and / or halogen, preferably chlorine or bromine, 20 Aryl or alkyl, preferably C1-C4 alkyl, and / or C7-C optionally substituted with halogen, preferably chlorine or bromine.12 It is aralkyl, n is independently 0 or 1, preferably 1; q is a number between 0 and 30, The process according to any one of the above aspects, wherein X is selected from the group consisting of a monocyclic or polycyclic aromatic radical having 6 to 30 carbon atoms, optionally substituted with OH and optionally having up to 8 ether bonds, or a linear or branched aliphatic radical having 2 to 30 carbon atoms.

[0156] 15. X in the general formula (IV) is the following: [ka] or their chlorinated or brominated derivatives.

[0157] 16. The process according to any one of the above aspects, characterized in that the material to be pyrolyzed contains, based on its total weight, a total amount of phosphorus-containing organic compounds in which phosphorus is present in the +5 formal oxidation state of 0.1% to 20.0% by weight, more preferably 0.5% to 15.0% by weight, and most preferably 2.0% to 12.0% by weight.

[0158] 17. The process according to any one of the above aspects, characterized in that in step (a), the ratio of the total weight of all phosphorus-containing organic compounds present in the material to be pyrolyzed in which phosphorus is present in the formal oxidation state of +5 to the total weight of all polycarbonate-containing compounds present in the material to be pyrolyzed is in the range of a weight ratio of 1:1000 to 1:5, more preferably 1:200 to 1:7, and most preferably 1:50 to 1:10.

[0159] 18. The process of any one of the preceding aspects, wherein the material to be pyrolyzed additionally comprises at least one polymer having structural units derived from styrene.

[0160] 19. The process according to embodiment 18, characterized in that the polymer having structural units derived from styrene is selected from at least one representative of the group formed by (impact-modified) polystyrene, styrene-acrylonitrile copolymer (SAN), acrylonitrile-butadiene-styrene terpolymer (ABS), methyl methacrylate-butadiene-styrene terpolymer (MBS), and butyl acrylate-styrene-acrylonitrile terpolymer (ASA).

[0161] 20. The process according to any one of the above aspects, characterized in that the polycarbonate-containing compound and the phosphorus-containing organic compound are present as a mixture in the same material, which is preferably introduced into the reactor in the form of solid particles, in particular in the form of a granular mixture.

[0162] 21. The process of any one of the preceding aspects, wherein the material to be pyrolyzed in step (a) additionally comprises at least one filler.

[0163] 22. The process according to any one of the above aspects, wherein the material to be pyrolyzed in step (a) contains, based on its total weight, the polycarbonate-containing compound and the phosphorus-containing organic compound in which phosphorus is in the +5 formal oxidation state in a total amount of 10.0% by weight to 80.0% by weight, more preferably 30.0% by weight to 70.0% by weight.

[0164] 23. Use of a pyrolysis device for producing a pyrolysis product from a material to be pyrolyzed, comprising at least one metering device for feeding the material to be pyrolyzed, at least one heatable reactor for pyrolysis and at least one pyrolysis product collector, for recovering at least one organic aromatic compound having one hydroxyl group by pyrolysis of a polycarbonate-containing compound in the presence of at least one phosphorus-containing organic compound in which phosphorus has a formal oxidation state of +5, The heatable reactor for pyrolysis comprises at least one heating element that can be used to control the temperature in the reactor at temperatures between 300 ° C and 700 ° C, and also at least one inlet for the material to be pyrolyzed and at least one separate outlet for the pyrolysis product, The metering device and the heatable reactor for pyrolysis are arranged and configured relative to each other such that the metering device is connected to an inlet for the material to be pyrolyzed of the heatable reactor for pyrolysis via at least one supply line; the heatable reactor for pyrolysis and the pyrolysis product collector are in fluid communication with each other so that the pyrolysis product, preferably gaseous, can be discharged from the pyrolysis product outlet and the discharged pyrolysis product can be introduced into the pyrolysis product collector, At least one pyrolysis product collector can be used to reduce the temperature of the pyrolysis product discharged from the reactor to less than 300°C in the collector to form a pyrolysis product selected from a pyrolysis product condensate, a pyrolysis product sublimate, or a mixture thereof, and is provided with at least one cooling device temperature-controlled to a temperature of less than 300°C, and at least one container for collecting and discharging the pyrolysis product obtained by cooling; Use, characterized in that at least one metering device for supplying material to be pyrolyzed, at least one heatable reactor for pyrolysis, and at least one pyrolysis product collector are arranged and configured relative to one another so that they can operate simultaneously.

[0165] 24. In each case based on the total weight of the composition: (i) at least one aromatic compound having less than 13% by weight of at least two hydroxyl groups, preferably bisphenol A; (ii) at least one aromatic compound having exactly one hydroxyl group, preferably a phenol, in an amount of more than 15% by weight; (iii) optionally further ingredients; A composition in the form of a condensed pyrolysis product obtainable by the process according to any one of aspects 1 to 22, comprising at least

[0166] 25. The composition according to embodiment 24, additionally containing (iv) at least one aromatic compound having more than 5% by weight of at least one vinyl substituent, preferably styrene or α-methylstyrene. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLES

[0167] Example 1: The following pyrolyzed materials were prepared by melt compounding in a ZSK25 twin-screw extruder (Coperion, Germany) at a melt temperature of 260°C.

[0168] [Table 1]

[0169] Pyrolysis process: The pyrolysis of the materials to be pyrolyzed according to the invention (compositions A and C) and of the material to be pyrolyzed not according to the invention (composition B) was carried out at 500° C. in a fixed-bed reactor under flowing Ar. The corresponding compositions were introduced into the reactor as drop-in samples (pellets, approximately 8 g) from a storage container into a sample crucible for melting the samples in the area of ​​the hot zone. The residence time of the materials to be pyrolyzed was 30 min. The flow rate (superficial velocity) of the gas stream in the reactor was 0.07 m / s. Downstream of the reactor, two condensers were installed to cool the pyrolysate and to separate and collect the liquid components of the pyrolysis products obtained. The content of the obtained carbonized material in the pyrolysis residue was determined by weighing the crucible after pyrolysis. The gases emerging from downstream of the two condensers were characterized by GC. The components of the pyrolysis products obtained in the form of oil were determined by GC-FID. This was carried out using an Agilent 7890A equipped with a Supelco SPB50 column. The pyrolysis oil was diluted 1:50 or 1:100 with acetone. The products, which are permanently gaseous at room temperature, were collected in gas bags and investigated by micro gas chromatography.

[0170] Results as percentages based on parts by weight of composition used:

[0171] [Table 2]

[0172] Example 2: The following pyrolysis target materials were produced by melt compounding in a ZSK25 twin screw extruder (Coperion, Germany) at a melt temperature of 260° C. (notes 1 to 6 from Example 1):

[0173] [Table 3]

[0174] Both Composition B and Composition C result in materials to be pyrolyzed according to the present invention.

[0175] The pyrolysis process described in Example 1 was carried out separately using each of the pyrolysis target materials A to F, and the condensation products of the pyrolysis products obtained in the form of oil were analyzed accordingly. The results of the analysis are as follows:

[0176] [Table 4]

[0177] It can be seen that the phenol content of the pyrolysis products from the pyrolysis of the pyrolysis target materials of compositions B and C (in each case containing organophosphorus compounds with a formal oxidation state of phosphorus of +5) is higher than the phenol content resulting from the pyrolysis of the pyrolysis products of the remaining compositions, either composition (A) containing no organophosphorus compounds at all, compositions ((D) and (E)) containing non-organophosphorus compounds with a formal oxidation state of phosphorus of +5, or composition (F) containing organophosphorus compounds with a formal oxidation state of phosphorus of +3. This contrast applies to compositions in which the same content of phosphorus is introduced.

Claims

1. At least the following steps: (a) introducing into a reactor a material to be pyrolyzed comprising at least one polycarbonate-containing compound and a total amount of phosphorus-containing organic compounds, said total amount relative to the total weight of the material to be pyrolyzed contributing at least 0.01% by weight of phosphorus having a formal oxidation state of +5, preferably at least 0.05% by weight of phosphorus having a formal oxidation state of +5, more preferably at least 0.1% by weight of phosphorus having a formal oxidation state of +5, and particularly preferably at least 0.5% by weight of phosphorus having a formal oxidation state of +5; (b) a step of decomposing at least the polycarbonate-containing compound introduced into the reactor in step (a) at a temperature of 300° C. to 700° C. to obtain a gas-phase product as a pyrolysis product and a non-gas-phase pyrolysis residue, (i) during the decomposition, the amount of oxygen gas in the reactor is 2.0 vol.% or less based on the total volume of gas present in the reactor; and (ii) discharging the pyrolysis product from the reactor during the decomposition; and (iii) discharging the pyrolysis residue from the reactor; (c) cooling the discharged pyrolysate to a temperature of less than 300° C. to obtain a pyrolysis product selected from a pyrolysate condensate, a pyrolysate resublimate, or a mixture thereof; (d) optionally post-treating the pyrolysis product; 1. A method for pyrolyzing a polycarbonate-containing compound, comprising:

2. 2. The method according to claim 1, characterized in that the temperature in step (b) is between 350°C and 650°C, preferably between 400°C and 650°C, particularly preferably between 420°C and 600°C, very particularly preferably between 450°C and 580°C.

3. 3. The method according to claim 1 or 2, characterized in that the discharge of the pyrolysis product from the reactor is ensured by a gas flow passing through the reactor, the flow rate of the gas flow as superficial velocity in the reactor being in the range of 0.01 m / s to 20 m / s.

4. The method according to any one of claims 1 to 3, characterized in that the polycarbonate-containing compound is at least one compound having an oxygen-functionalized aromatic structural fragment.

5. 5. The method according to claim 1, wherein the polycarbonate-containing compound is at least one compound obtained by reacting (i) at least one aromatic compound having at least two hydroxyl groups, preferably bisphenol A, with (ii) phosgene or diphenyl carbonate.

6. 6. The method according to claim 1, wherein the phosphorus-containing organic compound is selected from at least one compound of the group comprising organophosphates.

7. 7. The method according to claim 1, characterized in that the phosphorus-containing organic compound is selected from at least one compound of the group formed by organic phosphate monoesters, organic phosphate diesters, organic phosphate triesters, and organic oligomeric phosphate esters.

8. The phosphorus-containing organic compound comprises at least one compound of general formula (IV): 【Chemistry 1】 (In the formula, R １ , R ２ , R ３ and R ４ each independently represents an optionally halogenated C １ ~C ８ Alkyl, alkyl, preferably C １ ~C ４ C optionally substituted with alkyl and / or halogen, preferably chlorine or bromine ５ Or C ６ Cycloalkyl, alkyl, preferably C １ ~C ４ C optionally substituted with alkyl and / or halogen, preferably chlorine or bromine ６ ~C ２０ Aryl or alkyl, preferably C １ ~C ４ C optionally substituted with alkyl and / or halogen, preferably chlorine or bromine ７ ~C １２ It is aralkyl, n is independently 0 or 1, preferably 1; q is a number from 0 to 30; 8. The method according to claim 1 , wherein X is selected from the group consisting of a monocyclic or polycyclic aromatic radical having 6 to 30 carbon atoms, optionally substituted with OH and optionally having up to 8 ether bonds, or a linear or branched aliphatic radical having 2 to 30 carbon atoms.

9. X in the general formula (IV) is the following: 【Chemistry 2】 or their chlorinated or brominated derivatives.

10. 10. The method according to claim 1, wherein the material to be pyrolyzed additionally comprises at least one polymer having structural units derived from styrene.

11. 11. The method of claim 10, characterized in that the polymer having structural units derived from styrene is selected from at least one representative of the group formed by polystyrene, polybutadiene rubber modified polystyrene, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene terpolymer, methyl methacrylate-butadiene-styrene terpolymer, and butyl acrylate-styrene-acrylonitrile terpolymer.

12. 12. The method according to claim 1, characterized in that the polycarbonate-containing compound and the phosphorus-containing organic compound are present as a mixture in the same material, which is preferably introduced into the reactor in the form of solid particles, in particular in the form of a granular mixture.

13. The method according to any one of the preceding claims, characterized in that the material to be pyrolyzed in step (a) additionally comprises at least one filler.

14. 1. Use of a pyrolysis device for producing a pyrolysis product from a material to be pyrolyzed, comprising at least one metering device for feeding the material to be pyrolyzed, at least one heatable reactor for pyrolysis, and at least one pyrolysis product collector, for recovering at least one organic aromatic compound having one hydroxyl group by pyrolysis of a polycarbonate-containing compound in the presence of at least one phosphorus-containing organic compound in which phosphorus has a formal oxidation state of +5, The heatable reactor for pyrolysis comprises at least one heating element that can be used to control the temperature of the reactor at temperatures between 300° C. and 700° C., and also at least one inlet for the material to be pyrolyzed and at least one separate outlet for the pyrolysis product, The metering device and the heatable reactor for pyrolysis are arranged and configured relative to each other such that the metering device is connected to the inlet for the material to be pyrolyzed of the heatable reactor for pyrolysis via at least one supply line; and The heatable reactor for pyrolysis and the pyrolysis product collector are in fluid communication with each other so that a pyrolysis product, preferably gaseous, can be discharged from the pyrolysis product outlet and the discharged pyrolysis product can be introduced into the pyrolysis product collector; and The at least one pyrolysis product collector comprises at least one cooling device controlled to a temperature of less than 300° C. that can be used to reduce the temperature of the pyrolysis product discharged from the reactor to less than 300° C. to form a pyrolysis product selected from a pyrolysis product condensate, a pyrolysis product sublimate, or a mixture thereof, and at least one container for collecting and discharging the pyrolysis product obtained by cooling; and The use, characterized in that the at least one metering device for supplying material to be pyrolyzed, the at least one heatable reactor for pyrolysis, and the at least one pyrolysis product collector are arranged and configured relative to each other so that they can operate simultaneously.

15. In each case, based on the total weight of the composition, (i) at least one aromatic compound having less than 13% by weight of at least two hydroxyl groups, preferably bisphenol A; (ii) at least one aromatic compound having exactly one hydroxyl group, preferably phenol, in a total amount of more than 15% by weight; (iii) optionally further ingredients; A composition in the form of condensed pyrolysis products obtainable by the process according to any one of claims 1 to 13, comprising at least

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