Thermal decomposition of polycarbonate-containing materials for raw material recovery.

Abstract

The present invention relates to a method for thermally decomposing a polycarbonate-containing material in order to recover raw materials. [Solution] A pyrolysis process comprising at least the following steps: (a) introducing a material to be pyrolyzed, including a mixture of PC and PS, into a reactor; (b) decomposing at least the material to be pyrolyzed 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, wherein (i) during the decomposition, the amount of oxygen gas in the reactor is 2.0 volume% or less of the total volume of gas present in the reactor; (ii) during the decomposition, the pyrolysis product is discharged from the reactor; and (iii) the pyrolysis residue is discharged from the reactor; and (c) the discharged pyrolysis product is cooled to a temperature of less than 300°C to obtain a pyrolysis product selected from pyrolysis product condensate, pyrolysis product resublimation, or a mixture thereof.

Description

Background Art

[0001] Polycarbonate formulations, such as polycarbonate-containing materials like polycarbonate resins or polycarbonate composite resins, are used as materials for consumer goods. The corresponding polycarbonate resins or polycarbonate composite resins are produced by blending polycarbonate with other polymers, for example, by blending polycarbonate with acrylonitrile-butadiene-styrene (ABS). Since these polycarbonate-containing materials have excellent properties such as impact resistance, fluidity, toughness, and flame retardancy, they are used in many applications such as electronic devices and automobiles.

[0002] After the above-mentioned polycarbonate resins and polycarbonate composite resins are introduced into the market as elements of many products, they accumulate in waste as useful materials at the end of the product's service life. Most of the old products are sent for disposal and replaced by new products. As a result, the total amount of plastic waste generated is increasing year by year. Approximately 60% of this total waste is disposed of by incineration or landfill.

[0003] When plastic waste is incinerated, CO2 is emitted into the atmosphere, leading to global warming. Since plastic waste has a low density, it occupies a large volume in landfill sites, which may also lead to overall pollution in rivers and seas. Therefore, it is important to develop an efficient recycling method that can solve the waste problem and at the same time protect fossil resources.

[0004] Since the above-mentioned polycarbonate (composite) resins occupy approximately 8% of the polymer market, recycling of polycarbonate has not been the focus of development so far. However, in the future, since the plastic market will continue to grow, it is important to develop recycling technologies for all types of polymers in order to achieve both reduction of CO2 emissions and protection of fossil energy sources.

[0005] The process of recycling plastic waste can be broadly classified into three categories. (1) Mechanical recycling: Here, plastic waste can be melted again as it 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 decomposed into smaller molecules to obtain useful chemical raw materials. (3) Thermal recycling: Here, plastic waste is converted into off-gas and thermal energy.

[0006] New synthetic resins or other chemical products can be synthesized using the chemical raw materials obtained from thermochemical recycling.

[0007] Thermochemical recycling is called pyrolysis. In most cases, pyrolysis is used for packaging waste, and in a known purification process using crackers, pyrolysis oil is obtained, which is used as a certain type of recycled naphtha in the form of a drop-in solution. Little is known about the pyrolysis of polycarbonate in this pyrolysis process.

[0008] When a catalyst or additive is used in the pyrolysis process, the operating temperature can be reduced, the reaction time can be shortened, the decomposition efficiency can be increased, the product distribution can be restricted, and the process can be made more efficient. become.

[0009] When metal halide salts, particularly copper chloride and iron chloride catalysts, were used as catalysts, it was possible to generate a larger amount of phenolic compounds during the thermal decomposition of polycarbonate at 600°C compared to when no catalyst was used (Non-Patent Literature 1). Furthermore, with the aim of reducing carbonized residue, the catalytic thermal decomposition of polycarbonate was optimized using various metal chloride compounds (Non-Patent Literature 2). Since uncatalyzed thermal decomposition proceeds very slowly at 400°C, the effect of the catalyst was determined at 400°C (1 hour). The selection of metal chloride had a significant impact on the thermal decomposition. While NaCl, CrCl3, CuCl3, and AlCl3 did not improve the thermal decomposition rate, SnCl2 and ZnCl2 decomposed polycarbonate with a weight loss of over 80%.

[0010] The use of metal salts as catalysts also improved the product distribution in the thermal decomposition of polycarbonate. While the liquid product in the thermal decomposition of polycarbonate without a catalyst contained 11 different products, the mixture using ZnCl2 or SnCl2 as a catalyst contained only 7 major products, including bisphenol A, phenol, and diphenyl ether, with significantly lower levels of impurities.

[0011] For the thermal decomposition of polycarbonate-containing materials, catalysts consisting of metal oxides and zeolites with various porosities and acidity / basicity are also known (Non-Patent Documents 3 and 4).

[0012] Using basic catalysts such as CaO and MgO, the thermal decomposition temperature could be significantly reduced to 400°C to 450°C, and a liquid fraction containing a high proportion of phenolic compounds was simultaneously produced (Non-Patent Documents 5 and 6). It was demonstrated 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), the vapor pyrolysis of pure polycarbonate achieved better efficiency and a higher BPA yield (78%) at 300°C, while heating to 500°C with MgO produced a high proportion of phenol (84%) (Non-Patent Documents 7 and 8).

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

[0015] All of the pyrolysis processes described in the prior art are primarily intended for use as microgram-scale pyrolysis for analytical purposes and are therefore unsuitable for industrial or commercial use. Consequently, the pyrolysis presented in the prior art is carried out in all cases using pyrolysis equipment that is unsuitable for industrial or commercial use.

[0016] In particular, for the thermal decomposition of polycarbonate-containing materials containing larger amounts of polycarbonate in addition to other components, a novel process using an appropriate reactor that can reduce the influence of other components on the outcome of polycarbonate thermal decomposition is required. Even in the presence of other components, it is necessary to selectively obtain from polycarbonate-containing polymer mixtures cleavage products that can be reused for polycarbonate synthesis, especially thermal decomposition products containing high content of aromatic hydroxy compounds such as bisphenol A (BPA) or phenol. From the perspective of ghee, aromatic compounds having at least two hydroxyl groups, particularly aromatic compounds of the following general formula (I), can be directly reused in the production of polycarbonates in polycondensation reactions that do not involve further petrochemical conversion steps that consume a large amount of energy, and therefore it is preferable that they be largely recovered by thermal decomposition.

[0017] Furthermore, the novel pyrolysis process described above provides pyrolysis products that, in addition to the reusable cleavage products in the synthesis of polycarbonate, also contain large quantities of cleavage products of other components, such as styrene from polystyrene-containing materials, in good yield. These cleavage products are suitable for the production of the above-mentioned components in terms of circular recycling. [Prior art documents] [Patent Documents]

[0018] [Patent Document 1] U.S. Patent Application Publication No. 2007 / 0185309 [Non-patent literature]

[0019] [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 [Overview of the project] [Problems that the invention aims to solve]

[0020] Therefore, the objective was to provide a process and a pyrolysis apparatus usable in the process for the commercial implementation of pyrolysis, which allows for the pyrolysis of a material to be pyrolyzed, comprising at least a material containing a mixture of a polycarbonate-containing compound and a polystyrene-containing compound, and which, when used, yields a certain amount of pyrolysis product containing, preferably more than 40% by weight of cleavage products reusable for the synthesis of polycarbonate-containing materials and polystyrene-containing materials, relative to the total weight of the polycarbonate-containing material and polystyrene-containing material used, even when a relatively large amount of the material to be pyrolyzed is used. A further objective was to recover most aromatic compounds having at least two hydroxyl groups, in particular aromatic compounds of the following general formula (I), by pyrolysis of the material to be pyrolyzed, which contains a polycarbonate-containing compound. A further objective was also to recover most aromatic compounds having at least two hydroxyl groups, in particular aromatic compounds of the following general formula (I), and styrene by pyrolysis. [Means for solving the problem]

[0021] Therefore, this application relates to at least the following steps: (a) A step of introducing a material to be pyrolyzed, which includes at least a material containing a mixture of a polycarbonate-containing compound and a polystyrene-containing compound, into a reactor, (b) A step of decomposing at least the material to be thermally decomposed introduced into the reactor in step (a) at a temperature of 300°C to 700°C to obtain a gaseous product as a thermal decomposition product and a non-gas phase thermal decomposition residue, (i) During the above decomposition, the amount of oxygen gas in the reactor is between 0% and 2.0% by volume relative to the total volume of gas present in the reactor, (ii) During the above decomposition, the above thermal decomposition product is discharged from the reactor, (iii) A step of discharging the above-mentioned pyrolysis residue from the reactor, (c) A step of cooling the discharged pyrolysis product to a temperature of less than 300°C to obtain a pyrolysis product selected from pyrolysis product condensate, pyrolysis product resublimation, or a mixture thereof, (d) A step of optionally treating the pyrolysis product, It provides a thermal decomposition process that includes [the following].

[0022] The term "thermal decomposition material" refers to the entire substance that is introduced into a reactor for thermal decomposition and subjected to heat treatment there in the absence of oxygen gas or in the presence of a low amount of oxygen gas. Preferably, the thermal decomposition material is in solid form before being introduced into the reactor.

[0023] "Thermal decomposition products" is understood to mean the total amount of products formed by thermal decomposition that are in the gas phase (more specifically, in the form of gas and / or aerosol) within the reactor under the conditions of step (b).

[0024] "Thermal decomposition residue" is understood to mean the total of the substances formed by thermal decomposition and other residues of the material being thermally decomposed, which are not in the gas phase in the reactor under the conditions of step (b). An embodiment of the process characterized in that the thermal decomposition residue in the reactor is solid is preferred.

[0025] "Thermal decomposition products" are understood to mean the total products from the thermal decomposition products that accumulate by condensation and / or resublimation when the thermal decomposition products are cooled in step (c). The liquid thermal decomposition products are also called thermal decomposition oils.

[0026] Unless otherwise explicitly defined in relation to this, a substance (e.g., material, material to be pyrolyzed, pyrolysis product, pyrolysis residue) is a "liquid" if it is in a liquid state at 20°C and 10¹³ mbar. Unless otherwise explicitly defined in relation to this, a substance (e.g., material, material to be pyrolyzed, pyrolysis product, pyrolysis residue) is a "solid" if it is in a solid state at 20°C and 10¹³ mbar. Unless otherwise explicitly defined in relation to this, a substance (e.g., material, material to be pyrolyzed, pyrolysis product, pyrolysis residue) is a "gas" if it exists as a gas at 20°C and 10¹³ mbar.

[0027] A substance is considered "organic" if its chemical structure contains at least one carbon-hydrogen covalent bond.

[0028] In this application, the average molar mass specified for a polymer or polymer component is always the weight-average molar mass Mw unless otherwise explicitly stated. This can, in principle, be determined by gel permeation chromatography using an appropriate radioisotope detector for measurements against an external standard.

[0029] The "polycarbonate-containing compound" is selected from homopolymers or copolymers obtained by polyreaction, and at least one repeating unit is at least one * -OC(=O)-O- * (In the formula, * It is a polymer compound containing structural units (where represents the valency of the polymer backbone).

[0030] In the context of this application, “polystyrene-containing material” or “polystyrene-containing compound” is understood to mean a material or compound, preferably a polymer, that contains styrene or a styrene derivative, in particular a structural unit derived from styrene.

[0031] In this sense, the "polystyrene-containing compound" is selected from homopolymers or copolymers obtained by polymerization reactions, and has at least one repeating unit.* -CR 1 Ph-CH2- * (wherein * represents the valence of the polymer main chain, R 1 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 (especially chlorine)) is a polymer compound having a structural unit. In addition to at least one polycarbonate-containing compound, the above material is preferably in the form of at least one polymer in the form of a polystyrene-containing compound having at least one structural unit according to the above formula derived from 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 a mixture thereof. It is more preferable that R 1 in the above formula is H.

[0032] The "reactor" is the volume in which chemical conversion of the material from the material to be pyrolyzed occurs, for example, thermal decomposition occurs. In the case of thermal decomposition, this can be, for example, the volume of a heating container containing the material to be pyrolyzed.

[0033] According to the present invention, it is advantageous to introduce the material to be pyrolyzed into a reactor 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 rotary tube reactor, a fluidized bed reactor, and a drum reactor, according to the process of the present invention. More specifically, preferred reactors are those that can continuously introduce the material to be pyrolyzed, and are selected from a rotary tube reactor, a continuous stirred tank reactor (CSTR), a fixed bed reactor (especially a continuous bed exchange type with an internal heat exchanger, preferably an internal heat exchange tube (shaft reactor)), a screw reactor, a screw conveyor reactor, an entrainment-flow reactor, a rotary tube reactor, or a fluidized bed reactor. In one embodiment of the process, a very particularly preferred reactor is selected from a screw reactor, a rotary oven, or a fluidized bed. Further reactors preferred in the processes and embodiments thereof according to the present invention will be described in the embodiments of the pyrolysis apparatus and the catalyst-using processes of the present invention (see below).

[0034] According to the present invention, the material to be pyrolyzed introduced into the reactor includes at least one material comprising a mixture of a polycarbonate-containing compound and a polystyrene-containing compound.

[0035] In one embodiment of the process according to the present invention, the material to be pyrolyzed contains in all cases an amount of the above material totaling 10.0% to 80.0% by weight, more preferably 30.0% to 70.0% by weight, relative to the total weight of the material to be pyrolyzed.

[0036] It has been found that it is preferable to introduce the material to be pyrolyzed into the reactor in the form of solid particles (particularly in the form of a granular mixture). The granular mixture of the material is formed from a large number of loose solid particles of the material, which are known as grains. The term grain refers to powder (where the majority of grains are loose solid particles), dust (where the majority of grains are loose solid particles), granules (where the loose solid particles are aggregates of several grains), and the particulate components of other granular mixtures. The fluidity of the granular mixture relates to its ability to flow freely under its own gravity through a flow test funnel having an outlet with a diameter of 16.5 mm.

[0037] The solid particles of the above material introduced into the reactor, more specifically the loose solid particles of the granular mixture, have an average diameter of 0.01 mm to 5 cm, preferably 0.1 mm to 5 cm. 50.3 It is preferable to have (volume average). Average particle size X 50.3 This is determined by sieving or by using a Retsch Camsizer particle size analyzer.

[0038] Typically, the above materials can be, for example, homopolymers, copolymers, comb polymers, block polymers, or mixtures thereof.

[0039] This type of material, in addition to polystyrene-containing compounds, contains at least 10 polycarbonate-containing compounds. * -OC(=O)-O- * (In the formula, * It is particularly preferable that there be at least one compound containing a structural unit (where represents the valency of the polymer backbone).

[0040] Polycarbonate-containing compounds suitable for the process of the present invention are, for example, aromatic polycarbonates and / or aromatic polyester carbonates. These can be produced by methods known from the literature or by processes known from the literature (for example, for the production of aromatic polycarbonates, see Schnell, "Chemistry and Physics of..."). "Polycarbonates", Interscience Publishers, 1964, and German Patent Application Publication No. 1495 See also German Patent Application Publication No. 626, No. 2232877, No. 2703376, No. 2714544, No. 3000610, and No. 3832396. For example, see German Patent Application Publication No. 3007934 for the manufacture of aromatic polyester carbonates.

[0041] Aromatic polycarbonates usable as polycarbonate-containing compounds can be prepared, for example, by reacting a compound having at least two hydroxyl groups, particularly diphenol, with a carbonyl halogen, preferably phosgene and / or an aromatic dicarboxylic acid dihalide, preferably a benzenedicarboxylic acid dihalide, in an interfacial process that optionally uses a chain arresting agent, such as monophenol, and optionally a trifunctional or higher branching agent, such as triphenol or tetraphenol. They can also be produced via a melt polymerization process by reacting a compound having at least two hydroxyl groups, particularly diphenol, with, for example, diphenyl carbonate.

[0042] According to the present invention, this type of material can be advantageously used, wherein the polycarbonate-containing compound is at least one of the following compounds, namely (i) at least one aromatic compound having at least two hydroxyl groups, particularly preferably bisphenol A, and (ii) at least one compound obtained by reacting phosgene or diphenyl carbonate.

[0043] For the production of polycarbonate-containing compounds, it is preferable to use at least one aromatic compound having at least two hydroxyl groups selected from general formula (I): [ka] (In the formula, A may have a single bond, a C1-C5 alkylene, a C2-C5 alkylidene, a C5 or C6 cycloalkylidene, -O-, -SO-, -CO-, -S-, -SO2-, or a further aromatic ring optionally containing a heteroatom fused to it, C6-C 12 Arylene, or a radical of formula (II) or formula (III), [ka] In all cases, B is C1~C 12 Alkyl, preferably methyl, halogen, preferably chlorine and / or bromine, x is independently 0, 1, or 2 in each case. p is either 1 or 0. R 5 and R 6 Each X 1 Each can be individually selected, and each can be independently hydrogen or a C1-C6 alkyl group, preferably hydrogen, methyl, or ethyl. X 1 It is carbon, m is an integer between 4 and 7, preferably 4 or 5, provided that at least one atom X 1 Above R 5 and R 6 (Both are alkyl.)

[0044] Preferred aromatic compounds having at least two hydroxyl groups include hydroquinone, resorcinol, dihydroxydiphenol, 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)diisopropylbenzene, as well as cyclic brominated and / or cyclic chlorinated derivatives thereof.

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

[0047] Examples of chain-stopping agents suitable for the production of thermoplastic aromatic polycarbonates include phenol, p-chlorophenol, p-tert-butylphenol or 2,4,6-tribromophenol, as well as 4-[2-(2,4,4-trimethylpentyl)]phenol, 4-(1,3-tetramethylbutyl)phenol according to German Patent Application Publication No. 2842005, or monoalkylphenols or dialkylphenols with a total of 8 to 20 carbon atoms in the alkyl substituent, such as 3,5-di-tert-butylphenol, p-isooctylphenol, p-tert-octylphenol, p-dodecylphenol and 2-(3,5-dimethylheptyl)phenol and 4-(3,5-dimethylheptyl)phenol Examples include long-chain alkylphenols such as phenols. In all cases, the amount of chain arresting agent used is typically 0.5 mol% to 10 mol% relative to the total moles of aromatic compounds having at least two hydroxyl groups used.

[0048] In preferred embodiments of the present invention, the usable thermoplastic aromatic polycarbonate is preferably 20,000 g / mol to 40,000 g / mol, more preferably 24,000 g / mol to 32,000 g / mol, and particularly preferably 26,000 g / mol to 30,000 g / mol with an average molecular weight (weight-average M) measured by GPC (gel permeation chromatography) using a polycarbonate standard based on bisphenol A. w ) has.

[0049] Thermoplastic aromatic polycarbonates may be made branched by known methods, preferably by incorporating 0.05 mol% to 2.0 mol% of trifunctional or more compounds, such as those having three or more phenolic groups, relative to the total amount of aromatic compounds having at least two hydroxyl groups used.

[0050] It is preferable to use a linear polycarbonate, more preferably one based on bisphenol A.

[0051] Both homopolycarbonates and copolycarbonates are preferred. For the production of copolycarbonates that can be preferably used according to the present invention, 1% to 25% by weight, preferably 2.5% to 25% by weight, of polydiorganosiloxanes having hydroxyaryloxy-terminated groups can also be used, based on the total amount of aromatic compounds having at least two hydroxyl groups used. These are known (U.S. Patent No. 3,419,634) and can be produced by processes known from the literature. Polydiorganosiloxane-containing copolycarbonates are also preferred, and the production of polydiorganosiloxane-containing copolycarbonates is described, for example, in German Patent Application Publication No. 3334782.

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

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

[0054] In the production of polyester carbonates, halogenated carbonyls, preferably phosgene, are also used as additional bifunctional acid derivatives.

[0055] In addition to the monophenols already mentioned, useful chain arresters for the production of aromatic polyester carbonates include their chloroformate esters, as well as C1-C11 compounds. 22 Acid chlorides of aromatic monocarboxylic acids, which may optionally be substituted with alkyl groups or halogen atoms, and aliphatic C2-C2 atoms. 22 Examples include monocarboxylic acid chlorides.

[0056] The amount of the chain arrester is 0.1 mol% to 10 mol% in both cases: phenolic chain arresters are relative to the moles of the aromatic compound having at least two hydroxyl groups, and monocarboxylate chloride chain arresters are relative to the moles of the dicarboxylate.

[0057] In the production of aromatic polyester carbonates, one or more aromatic hydroxycarboxylic acids can also be used.

[0058] The aromatic polyester carbonate may be linear or branched by known methods (see German Patent Application Publication No. 2940024 and German Patent Application Publication No. 3007934), but linear polyester carbonate is preferred.

[0059] The branching agents used are, for example, trifunctional or polyfunctional carboxylic acid chlorides such as trimesil trichloride, cyanuryl 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)hepta-2-ene, 4,6-dimethyl-2,4,6-tri(4-hydroxyphenyl)heptane, 1,3,5-tri(4-hydroxyphenyl)benzene, 1, The branching agent can 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, or 1,4-bis[4,4'-dihydroxytriphenyl)methyl]benzene. The phenolic branching agent should be added first along with the diphenol, while the acid chloride branching agent should be introduced along with the acid dichloride.

[0060] The proportion of carbonate structural units in thermoplastic aromatic polyester carbonate can be varied as desired. Preferably, the proportion of carbonate groups is up to 100 mol%, particularly up to 80 mol%, and more preferably up to 50 mol%, relative to the total of ester groups and carbonate groups. Both the ester and carbonate portions of the aromatic polyester carbonate can exist in block form or in a random distribution in the polycondensate.

[0061] Aromatic polycarbonates and polyester carbonates can be used alone or in any desired mixture in the above materials for the process according to the present invention.

[0062] The above-mentioned material of the material to be thermally decomposed includes at least one polycarbonate-containing compound, in addition to at least one polystyrene-containing compound.

[0063] In the context of this application, “polystyrene-containing material” is understood to mean a compound, preferably a polymer, that contains styrene or a styrene derivative, in particular a structural unit derived from styrene.

[0064] Therefore, according to the present invention, "polystyrene-containing compound" is understood to mean a compound containing repeating units derived from styrene (especially styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, etc.) that are optionally substituted on the aromatic ring.

[0065] In one embodiment of the process according to the present invention, in addition to at least one polycarbonate-containing compound, at least 10 formulas: * -CR 1 Ph-CH2- * (In the formula, * This represents the valency of the repeating unit of the polymer backbone. R 1 The compound comprises at least one polymer in the form of a polystyrene-containing compound having repeating units of (where 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 (particularly chlorine)). It is advantageous to use a material containing styrene (R) in the material to be thermally decomposed. The above material contains at least one polycarbonate-containing compound, in addition to 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 It is particularly preferable to include at least one polymer in the form of a polystyrene-containing compound having at least 10 repeating units of the above formula derived from (=H, Ph=4-chlorophenyl) or a mixture thereof.

[0066] Materials that can be preferably used in accordance with the present invention include, in addition to at least one polycarbonate-containing compound, at least one additional polystyrene-containing compound selected from rubber-modified graft polymers (B1) having structural units derived from styrene or styrene derivatives, or rubber-free vinyl (co)polymers (B2) having structural units derived from styrene or styrene derivatives, or mixtures of two or more such polymers.

[0067] The rubber-modified graft polymer (B1) that is preferably used is B.1.1 With respect to component B.1, 5% to 95% by weight, preferably 15% to 92% by weight, and particularly 25% to 60% by weight of a vinyl aromatic compound and / or a ring-substituted vinyl aromatic compound (styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, etc.) is added. B.1.2 On one or more rubbery graft bases having a glass transition temperature of preferably less than 10°C, more preferably less than 0°C, and especially preferably less than -20°C, in an amount of 95% to 5% by weight, preferably 85% to 8% by weight, and particularly 75% to 40% by weight relative to component B.1, include.

[0068] 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. g It is defined as the midpoint temperature (tangential method).

[0069] Graft base B.1.2 typically has a median particle size (d) of 0.05 μm to 10 μm, preferably 0.1 μm to 5 μm, and more preferably 0.2 μm to 1 μm. 50 ) has a median particle size d50 This is the diameter at which 50% by weight of the particles are present in larger and smaller diameters, respectively. 50 This can be determined by ultracentrifugation (W. Scholtan, H. Lange, Kolloid, Z. und Z. Polymere 250 (1972), 782-1796).

[0070] Monomer B.1.1 is, B.1.1.1 For B.1.1, 50 to 99 parts by weight, preferably 60 to 80 parts by weight, particularly 70 to 80 parts by weight of a vinyl aromatic compound and / or a ring-substituted vinyl aromatic compound (particularly selected from styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, or mixtures thereof), B.1.1.2 With respect to 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 nitriles such as acrylonitrile and methacrylonitrile) and / or C1 to C8 alkyl (meth)acrylates and / or unsaturated carboxylic acid derivatives (anhydrides and imides, etc.), such as methyl methacrylate, n-butyl acrylate, tert-butyl acrylate, etc., for example maleic anhydride and N-phenylmaleimide, It is preferable that it be a mixture of the following.

[0071] Preferred monomers B.1.1.1 are the monomers styrene and α-methylstyrene. At least one of the following is selected, and the preferred monomer B.1.1.2 is 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.

[0072] Suitable graft bases B.1.2 for graft polymer B.1 include diene rubber, EP(D)M rubber, i.e., ethylene / propylene and optionally diene-based rubber, acrylate rubber, polyurethane rubber, silicone rubber, chloroprene rubber and ethylene / vinyl acetate rubber, as well as silicone / acrylate composite rubber.

[0073] Preferred graft bases B.1.2 are, for example, diene rubber or mixtures of diene rubber based on butadiene and isoprene, or copolymers of diene rubber or mixtures thereof with further copolymerizable monomers (e.g., according to B.1.1.1 and B.1.1.2).

[0074] A particularly preferred graft base B.1.2 is pure polybutadiene rubber.

[0075] Particularly preferred as polymer B1 are polymers selected from, for example, acrylonitrile-butadiene-styrene copolymer (also known as ABS polymer) or methacrylate-butadiene-styrene copolymer (also known as MBS polymer), as described in, for example, German Patent Application Publication No. 2035390 (= U.S. Patent No. 3644574) or German Patent Application Publication No. 2248242 (= UK Patent Application Publication No. 1409275) or Ullman's Encyclopedia of Industrial Chemistry, Vol. 19 (1980), p. 280ff.

[0076] Graft copolymer B.1 is produced by free radical polymerization, such as emulsion polymerization, suspension polymerization, solution polymerization, or bulk polymerization, preferably emulsion polymerization or bulk polymerization.

[0077] The gel content of graft base B.1.2 is, in all cases, at least 30% by weight, preferably at least 40% by weight, and particularly at least 60% by weight, relative to B.1.2, as measured as the insoluble fraction in toluene.

[0078] The gel content of graft base B.1.2 can be determined as the insoluble content in suitable solvents at 25°C (M. Hoffmann, H. Kroemer, R. Kuhn, Polymeranalytik I und II, Georg Thieme-Verlag, Stuttgart 1977).

[0079] A particularly suitable graft rubber is ABS polymer, which is produced by redox initiation using an initiator system consisting of an organic hydroperoxide and ascorbic acid, in accordance with U.S. Patent No. 4,937,285.

[0080] Since graft monomers are not always completely grafted onto the graft base in the graft reaction, according to the present invention, graft polymer B.1 is understood to result from the (co)polymerization of graft monomers in the presence of a graft base and also include products obtained during the process. Therefore, these products may also include free (co)polymers of graft monomers, i.e., (co)polymers that are not chemically bonded to rubber.

[0081] Monomers having two or more polymerizable double bonds may be copolymerized for crosslinking purposes. Preferred examples of crosslinking monomers include unsaturated monocarboxylic acids having 3 to 8 carbon atoms, such as ethylene glycol dimethacrylate and allyl methacrylate, and unsaturated monocarboxylic acids having 3 to 12 carbon atoms. Examples include esters with valence alcohols or saturated polyols having 2 to 20 carbon atoms and 2 to 4 OH groups; polyunsaturated heterocyclic compounds such as trivinyl and triallyl cyanurate; and 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, triacryloyl hexahydro-s-triazine, and triallylbenzene. The amount of crosslinking monomer is preferably 0.02% to 5% by weight, particularly 0.05% to 2% by weight, relative to 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 graft base B.1.2.

[0082] Preferred "other" polymerizable ethylenically unsaturated monomers that can be optionally used with acrylic acid esters for the preparation of graft base B.1.2 include, for example, acrylonitrile, styrene, α-methylstyrene, acrylamide, vinyl C1-C6 alkyl ethers, methyl methacrylate, and butadiene. A preferred acrylate rubber as graft base B.1.2 is an emulsion polymer having a gel content of at least 60% by weight.

[0083] Other preferred graft bases according to B.1.2 are silicone rubbers having graft active sites, as described in German Patent Publication Nos. 3704657, 3704655, 3631540, and 3631539.

[0084] The rubber-free vinyl (co)polymer according to component B.2 is preferably a rubber-free homopolymer and / or copolymer of at least one monomer from the group including vinyl aromatic compounds, vinyl cyanide (unsaturated nitrile), C1-C8 alkyl (meth)acrylates, unsaturated carboxylic acids, and unsaturated carboxylic acid derivatives (anhydrides and imides).

[0085] B.2.1 In all cases, 10% to 100% by weight, preferably 50% to 99% by weight, more preferably 60% to 80% by weight, and particularly 70% to 80% by weight, of at least one monomer selected from the group including vinyl aromatic compounds (e.g., styrene, α-methylstyrene) and ring-substituted vinyl aromatic compounds (e.g., p-methylstyrene, p-chlorostyrene), based on the total weight of (co)polymer B.2, B.2.2 In all cases, with respect to the total weight of (co)polymer B.2, 0% to 90% by weight, preferably 1% to 50% by weight, more preferably 20% to 40% by weight, and particularly 20% to 30% by weight, at least one monomer selected from the group including vinyl cyanide, for example unsaturated nitriles such as acrylonitrile and methacrylonitrile, C1 to C8 alkyl (meth)acrylates, for example methyl methacrylate, n-butyl acrylate and tert-butyl acrylate, unsaturated carboxylic acids and unsaturated carboxylic acid derivatives, for example maleic anhydride and N-phenylmaleimide, (Co)polymer B.2 obtained from is particularly preferred.

[0086] These (co)polymers B.2 are resinous, thermoplastic, and rubber-free. The above material is particularly preferably a copolymer of B.2.1 styrene and / or a homopolymer of B.2.1.

[0087] This type of (co)polymer B.2 is known and can be produced by free radical polymerization, particularly emulsion polymerization, suspension polymerization, solution polymerization or bulk polymerization. The (co)polymer is Preferably, the average molecular weight M is in the range of 15,000 g / mol to 250,000 g / mol, and more preferably in the range of 80,000 g / mol to 150,000 g / mol. w (It has a weight average obtained by GPC using polystyrene as the standard.)

[0088] The materials subject to thermal decomposition may, in addition to at least one polycarbonate-containing compound and at least one polystyrene-containing compound, further include flame retardants, drip inhibitors, flame retardant synergists, smoke inhibitors, lubricants and mold release agents, nucleating agents, antistatic agents, conductive additives, stabilizers (e.g., hydrolysis, thermal aging and UV stabilizers, and also transesterification inhibitors), flow promoters, phase-compounding agents, further polymer components other than components A and B (e.g., functional compounding materials), fillers and reinforcing agents, and at least one polymer additive selected from dyes and pigments.

[0089] It was found that limiting the materials to be pyrolyzed to those with a low content of phosphorus-containing organic compounds or those that do not contain such compounds can increase the content of aromatic compounds having at least two hydroxyl groups in the pyrolysis product, and therefore allow for recovery in high content. It was found that an appropriate specified total amount of phosphorus-containing organic compounds is 0% to 0.5% by weight of phosphorus, preferably 0% to 0.1% by weight of phosphorus, more preferably 0% to 0.05% by weight of phosphorus, and particularly preferably 0% to 0.01% by weight of phosphorus, in proportion to the total weight of the materials to be pyrolyzed. The technical effects resulting from this specified total amount were also achieved for materials to be pyrolyzed containing at least one polycarbonate-containing compound, a correspondingly limited total amount of phosphorus-containing organic compounds, and optionally, additionally, at least one polystyrene-containing compound.

[0090] Therefore, a further embodiment of the process according to the present invention is that, according to step (a), the material to be pyrolyzed is, At least one polycarbonate-containing compound, The proportion of phosphorus-containing organic compounds based on a certain total amount is defined such that, relative to the total weight of the material to be thermally decomposed, the phosphorus-containing organic compounds are 0% to 0.5% by weight or less of phosphorus, preferably 0% to 0.1% by weight or less of phosphorus, more preferably 0% to 0.05% by weight or less of phosphorus, and particularly preferably 0% to 0.01% by weight or less of phosphorus. Optionally, at least one polystyrene-containing compound, This process is characterized by including the following:

[0091] For the simultaneous recovery of styrene and its derivatives, it is even more preferable that the material to be pyrolyzed includes at least a material comprising a mixture of a polycarbonate-containing compound and a polystyrene-containing compound, and the above total amount of a phosphorus-containing organic compound.

[0092] In further embodiments, it has been found that according to the present invention, the phosphorus-containing organic compound that may exist only in limited amounts is preferably selected from phosphorus-containing organic compounds having a formal oxidation state of +5 for phosphorus.

[0093] Furthermore, it was found to be particularly preferable that the material to be thermally decomposed does not contain phosphorus-containing organic compounds in which at least one phosphorus atom has a formal oxidation state of +5.

[0094] Phosphorus-containing organic compounds that may be present only in limited amounts are preferred to be at least one compound selected from the group consisting of organic phosphate esters, organic phosphonic acid esters, organic phosphazenes, and phosphonic acid amines, particularly organic phosphate esters and organic phosphonic acid esters. Phosphorus-containing organic compounds are particularly preferred to be at least one compound selected from the group consisting of organic phosphate monoesters, organic phosphate diesters, organic phosphate triesters, and oligomeric phosphate esters. Therefore, using a mixture of two or more of these compounds is preferable. It is also possible, and this too can only exist in limited quantities.

[0095] In preferred embodiments, the phosphonate amines and phosphazenes that may be present in limited amounts in the material to be pyrolyzed may be, for example, those described in International Publication No. 00 / 00541 and International Publication No. 01 / 18105.

[0096] For the purposes of the present invention, particularly preferred phosphorus-containing organic compounds that may be present only in limited amounts are compounds of general formula (IV): [ka] (In the formula, R 1 , R 2 , R 3 and R 4 Each of these is an optionally halogenated C1-C8 alkyl group, in all cases an alkyl group, preferably a C1-C4 alkyl group and / or halogen, preferably a C5 or C6 cycloalkyl group optionally substituted with chlorine or bromine, and C6-C 20 Aryl or C7~C 12 It is Aralkir, n is independently either 0 or 1. q is between 0 and 30. X is a polycyclic aromatic radical having 12 to 30 carbon atoms, or a linear or branched aliphatic radical having 2 to 30 carbon atoms, which may be OH substituted and may have up to 8 ether bonds.

[0097] R in equation (IV) 1 , R 2 , R 3 and R 4 Each of these is preferably independently a C1-C4 alkyl, phenyl, naphthyl, or phenyl-C1 alkyl-phenyl-C4 alkyl group. Next, the aromatic group R 1 , R 2 , R 3 and R 4The radical may be substituted with a halogen and / or alkyl group, preferably chlorine, bromine and / or C1-C4 alkyl groups. Particularly preferred aryl radicals are cresyl, phenyl, xylenyl, propylphenyl, or butylphenyl, as well as their corresponding brominated and chlorinated derivatives.

[0098] In formula (IV), X is preferably a polycyclic aromatic radical having 12 to 30 carbon atoms. This is preferably derived from an aromatic compound having at least two hydroxyl groups of general formula (I). In equation (IV), n can independently be 0 or 1, and n is preferably 1. q has an integer value between 0 and 30, preferably between 0 and 20, more preferably between 0 and 10, or, in the case of a mixture, has an average value between 0.8 and 5.0, preferably between 1.0 and 3.0, even more preferably between 1.05 and 2.00, and particularly preferably between 1.08 and 1.60. In equation (IV), X is, in particular, [ka] Or it represents a chlorinated or brominated derivative thereof, and in particular, X is derived from bisphenol A or diphenylphenol. X is particularly preferably derived from bisphenol A.

[0099] The phosphorus compounds of formula (IV) are particularly tributyl phosphate, triphenyl phosphate, tricresyl phosphate, diphenyl cresyl phosphate, diphenyloctyl phosphate, diphenyl 2-ethyl cresyl phosphate, tri(isopropylphenyl) phosphate, and oligophosphates linked by bisphenol A. It is especially preferable to use oligomeric phosphate esters of formula (IV) derived from bisphenol A.

[0100] As a phosphorus-containing organic compound that may only be present in limited amounts, it is most preferable to use an oligophosphate based on bisphenol A, shown in formula (IVa). [ka]

[0101] The phosphorus organic compounds described above are known (see, for example, European Patent Application Publication No. 363608 and European Patent Application Publication No. 640655) or can be similarly prepared by known methods (e.g., Ullmann 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).

[0102] Suitable phosphorus-containing organic compounds according to the present invention, which may exist only in limited amounts, include, for example, organic phosphate esters having different chemical structures and / or mixtures of organic phosphate esters having the same chemical structure but different molecular weights.

[0103] When using oligomeric phosphate esters as phosphorus-containing organic compounds that may only exist in limited amounts, it is preferable to use a mixture of compounds having the same structure but different chain lengths. Here, the q values ​​shown in formulas (IV) and (IVa) are average q values. The average q value is a The phosphorus compound's composition (molecular weight distribution) is determined using high-performance liquid chromatography (HPLC) at 40°C in a mixture of cetonitrile and water (50:50), and the average value of q is calculated from this.

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

[0105] The metering and processing of the material to be pyrolyzed in the pyrolysis process of the present invention can be simplified by including at least one filler in addition to the material in step (a). Preferably, the filler does not catalytically affect the thermal decomposition of polycarbonate during pyrolysis. Therefore, it is particularly preferable that the filler is at least one metal oxide, preferably selected from SiO2, that does not exhibit catalytic activity for the thermal decomposition of polycarbonate during pyrolysis.

[0106] It is preferable to mix the polycarbonate material with a filler, such as sand, to further simplify the continuous process control of the process according to the present invention. In particular, adhesion of the material in the reactor and during supply from the metering device to the reactor is avoided. In one embodiment, the filler and the material are supplied to the material to be pyrolyzed as a mixture in which the volume ratio of the filler to the material is at least 0.1:1 to 10:1.

[0107] Using a catalyst allows for a more selective and efficient pyrolysis process. In one embodiment of the process according to the present invention, if the material to be pyrolyzed introduced in step (a) includes, in addition to the material, at least one catalyst that affects the decomposition reaction of the material, a more effective and selective decomposition can be obtained. A suitable catalyst can lower the pyrolysis temperature, reduce the product spectrum to the desired product, and optionally minimize carbonization. For an efficient process, an inexpensive catalyst is preferred. For example, naturally derived materials that can be arbitrarily ion-exchanged in a simple ion-exchange process, such as inorganic salts, refractory oxides, minerals, and industrial stones, can be used as catalysts because they do not require large-scale synthesis. They are readily available and therefore relatively inexpensive. On the other hand, synthetic catalysts such as zeolites (e.g., types ZSM-5, A, X, Y, etc.) are effective but are not inexpensive because they need to be specially manufactured.

[0108] In addition to its catalytic function, catalysts can also simplify the measurement and processing of materials to be pyrolyzed during thermal decomposition. Using a catalyst can reduce the amount of filler used in this case. In one embodiment, the total amount of filler and catalyst is supplied to the material to be pyrolyzed as a mixture in which the volume ratio of the amount of the above materials is at least 0.1:1 to 10:1.

[0109] In the pyrolysis reaction, it is preferable to select at least one catalyst from the group consisting of alkaline inorganic materials, and more preferably from the group of naturally derived materials defined above. These inorganic materials can be refractory oxides. Refractory oxides are metal oxides that are stable at high temperatures of 300°C to 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 aluminosilicate, aluminum silicon phosphate, silicalite, spinel, and others, including natural zeolites and clays. Therefore, particularly suitable as catalysts are at least one compound selected from the group consisting of inorganic salts, minerals, metal oxides, mixed oxides, clays, and zeolites.

[0110] Both homogeneous and heterogeneous catalysts can be used, but the process according to the present invention is preferable In a preferred embodiment, 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 (particularly in the form of a granular mixture). The heterogeneous catalyst used is its solid particles, or more specifically, its granular mixture, in which the average particle size is the average diameter X of the loose solid particles. 50.3 The (volume average) is preferably 0.01 mm to 5 cm, more preferably 0.1 mm to 5 cm. 50.3 This is determined by sieving or by using a Retsch Camsizer particle size analyzer.

[0111] In a more preferred embodiment, when using a heterogeneous catalyst, it has been found that the catalyst particles are particularly preferable to be smaller than or the same particle size as the particles of the material mentioned above. Therefore, it is preferable that the average particle size of the catalyst present in the material to be pyrolyzed corresponds at most to the average particle size of the material present in that material to be pyrolyzed.

[0112] A particularly preferred catalyst is a material to be pyrolyzed that may contain at least one basic catalyst. In the case of a solid basic catalyst, the number and strength of basic centers in the catalyst can be determined by Fourier transform infrared spectroscopy and thermal desorption of CO2 (TPD-CO2), or by using a standard titration method.

[0113] When a catalyst is added, it can be mixed with the filler, coated onto the filler, or used in place of the filler.

[0114] Since the catalyst used in the process according to the present invention tends to form deposits of carbonized material and other carbon residues, when using a catalyst, it is preferable to use a reactor that can easily and preferably discharge the catalyst and regenerate it continuously. Therefore, the use of a continuous stirred tank reactor (CSTR), moving bed reactor, screw reactor, screw conveyor reactor, jet reactor, rotary cone reactor, or fluidized bed reactor is preferred over the use of a fixed bed reactor.

[0115] Inactivated catalysts (e.g., those inactivated by carbonization) are present in the pyrolysis residue, but after the pyrolysis residue is discharged from the reactor, it can be supplied to a regenerator and, after regeneration, introduced into the pyrolysis reactor in addition to the pyrolysis material in step (b). Reactors that allow for short contact times, intensive mixing of the catalyst with the feed stream components, and continuous recycling of the regenerated catalyst into the pyrolysis zone are most preferred. This applies to screw reactors, rotary ovens, or fluidized beds, and these reactors are particularly preferred.

[0116] In step (a), the material to be pyrolyzed, introduced into the reactor, is at least partially decomposed according to step (b), forming pyrolysis products and pyrolysis residues.

[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 in the results of the process according to the present invention can be achieved in one embodiment by controlling the temperature of the introduced material to be pyrolyzed at 300°C to 700°C, and once this target temperature is reached, by setting the residence time of the correspondingly temperature-controlled material to 1 second to 2 hours, preferably 2 minutes to 60 minutes, until the time for discharge of the pyrolysis residue obtained from this material. The temperature and content of the oxygen gas in the reactor during this time are the values ​​specified in step (b).

[0118] If the material to be pyrolyzed in the process according to the present invention contains a catalyst, this catalyst is present in the discharged pyrolysis residue. Therefore, in a further embodiment of the process, the aforementioned discharged pyrolysis residue is supplied to a step for regenerating the catalyst contained therein.

[0119] Independently thereof, the discharge of pyrolysis products from the reactor in step (b) is carried out by a gas flow passing through the reactor or by suction, and more preferably in step (a). Good results can be achieved by ensuring that the residence time of the pyrolysis product, which is the time between the introduction time of the above-mentioned material into the receiver and the discharge time of the pyrolysis product, is 0.1 seconds to 10 seconds, preferably 0.5 seconds to 5 seconds, and more preferably 0.5 seconds to 2 seconds.

[0120] When a gas stream is passed through the reactor for this purpose, the gas used for the gas stream is preferably an inert gas selected from nitrogen, argon, CO2, NO, or a mixture thereof.

[0121] When using a gas flow to discharge pyrolysis products, according to the present invention, it is preferable that the flow rate of the gas flow in the reactor as an empty tower velocity is in the range of 0.01 m / sec to 20 m / sec. When a fixed-bed reactor is selected as the reactor, according to the present invention, it is preferable that the flow rate of the gas flow in the reactor as an empty tower velocity is in the range of 0.03 m / sec to 1 m / sec. When a fluidized-bed reactor is selected as the reactor, according to the present invention, it is preferable that the flow rate of the gas flow in the reactor as an empty tower velocity is in the range of 0.5 m / sec to 2 m / sec. When a jet reactor is selected as the reactor, according to the present invention, it is preferable that the flow rate of the gas flow in the reactor as an empty tower velocity is in the range of 5 m / sec to 20 m / sec.

[0122] The conditions for decomposition in the thermal decomposition in step (b) of the present invention are as follows: the temperature inside the reactor is 300°C to 700°C, and the amount of oxygen gas in the reactor is 0% to 2.0% by volume relative to the total volume of gas present in the reactor.

[0123] According to the present invention, the amount of oxygen gas is determined by filling a reactor, which is packed with the material to be pyrolyzed, with an inert gas, particularly nitrogen, argon, CO2, NO, or a mixture thereof. The inert gas may also be further mixed with a reactive gas other than oxygen gas, particularly a gas selected from methane, gaseous H2O, hydrogen gas, or a mixture thereof.

[0124] To minimize the intrusion of oxygen gas into the reactor upon introduction of the material to be pyrolyzed, the oxygen gas can be removed from the material to be pyrolyzed before its introduction in step (a), for example, by stripping it in a storage container upstream of the reactor, for example, using a stripping gas. For example, an inert gas, more specifically nitrogen, argon, CO2, NO, or a mixture thereof, can be passed through the storage container as a stripping gas from above or below (preferably from above) via frit, and then passed through the material to be pyrolyzed to expel the oxygen gas.

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

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

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

[0128] A preferred embodiment of the process provides continuous process control. For this purpose, continuous process control In the context of process control, at least steps (a) and (b) are performed simultaneously.

[0129] The pyrolysis products obtained according to step (c) can be treated using standard separation methods to obtain (i) at least one aromatic compound having at least two hydroxyl substituents, preferably bisphenol A, and (ii) at least one aromatic compound having at least one vinyl substituent, preferably styrene. A standard method for obtaining BPA is by crystallization or precipitation in toluene of the BPA / phenol adduct. Another option is distillation or extraction of BPA from the pyrolysis product mixture. Other products such as styrene or phenol can be separated by distillation.

[0130] The process according to the present invention can be carried out using a appropriately configured pyrolysis apparatus. Therefore, the present invention is a pyrolysis apparatus for producing pyrolysis products from a material to be pyrolyzed, comprising at least one metering device for supplying a material to be pyrolyzed, at least one heatable reactor for pyrolysis, and at least one pyrolysis product collector, The above-mentioned pyrolysis-heatable reactor comprises at least one heating unit that can be used to control the temperature in the reactor at a temperature of 300°C to 700°C, and 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 reactor are arranged and configured in relation to each other such that the metering device is connected via at least one supply line to the inlet for the material to be pyrolyzed in the pyrolysis-heatable reactor. Preferably, the pyrolysis reactor and the pyrolysis collector are in fluid communication with each other so that the gaseous pyrolysis product 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 lower the temperature of the pyrolysis products discharged from the reactor to below 300°C within the collector to form pyrolysis product selected from pyrolysis product condensates, pyrolysis product resublimations, or mixtures thereof, and comprises at least one cooling device temperature-controlled to below 300°C, and at least one container for collecting and discharging the pyrolysis product obtained by cooling. The present invention further provides a pyrolysis apparatus characterized in that at least one measuring device for supplying the material to be pyrolyzed, at least one heatable reactor for pyrolysis, and at least one pyrolysis product collector are arranged and configured in relation to each other so that they can operate simultaneously.

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

[0132] In a preferred embodiment, the reactor further includes at least one connection to a gas source, wherein a gas flow in the reactor, preferably with a flow rate as an empty tower velocity of 0.01 m / s to 20 m / s, flows through the reactor to a pyrolysis product collector via a regulator, such as a valve. When a fixed-bed reactor is selected as the reactor, according to the present invention, the flow rate as an empty tower velocity of the gas flow in the reactor is preferably in the range of 0.03 m / s to 1 m / s. When a fluidized-bed reactor is selected as the reactor, according to the present invention, the flow rate as an empty tower velocity of the gas flow in the reactor is preferably in the range of 0.5 m / s to 2 m / s. When a jet reactor is selected as the reactor, according to the present invention, the flow rate as an empty tower velocity of the gas flow in the reactor is preferably in the range of 5 m / s to 20 m / s.

[0133] As mentioned above, the gas flow from the gas source may be heated, for example, by a heating unit, before being introduced into the reactor.

[0134] The pyrolysis product collector of the apparatus according to the present invention collects pyrolysis products discharged from the reactor within this collector. It is preferable to have a cooling device that can be used to lower the temperature of the material to below 50°C (more preferably below 30°C) to form thermal decomposition products. A cooling unit that operates according to the principle of a heat exchanger is particularly suitable for this purpose.

[0135] According to the present invention, “fluid communication” is understood to mean a part of a device that connects parts of a system to each other, thereby enabling the transport of a substance, which may be in any physical state, 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 of the subject of the present invention described above for the recovery of an organic compound having at least two hydroxyl groups used in the production of a polycarbonate-containing compound by simultaneous pyrolysis of a polycarbonate-containing compound and a polystyrene-containing compound, and for the simultaneous recovery of styrene used in the production of a polystyrene-containing compound.

[0137] In the preferred embodiment of the above use, the pyrolysis apparatus is used not only for simultaneous styrene recovery but also for the recovery of bisphenol A used in the production of polycarbonate-containing compounds.

[0138] The process and apparatus according to the present invention contribute to achieving the above-mentioned objectives, and in step (c) of the process, in either case, with respect to the total weight of the composition, (i) at least one aromatic compound having at least two hydroxyl groups in a total amount of 25% to 80% by weight, preferably an aromatic compound according to the above general formula (I), very preferably bisphenol A, (ii) At least one aromatic compound having exactly one hydroxyl group in a total amount of more than 1% by weight, preferably phenol, (iii) At least one aromatic compound having at least one vinyl substituent in a total amount of more than 1.5% by weight, preferably styrene or α-methylstyrene, It includes at least, Here, a composition is provided as a thermal decomposition product in which the sum of the weight percentages of components (i) to (iii) and the weight percentages of the other components of the composition is 100% by weight.

[0139] It is preferable that the composition contains a small amount of high-boiling-point components. Therefore, a preferred embodiment of the composition described above contains, in a total amount of 0.5% to 10.0% by weight, at least one hydroxyl-free organic compound having a boiling point of at least 300°C at 10¹³ mbar.

[0140] Similarly, in preferred embodiments, the composition contains in a total amount of 25% to 80% by weight aromatic compounds having at least two hydroxyl groups selected from 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, or mixtures thereof.

[0141] It is even more preferable to combine the above-described features of component (i) and component (ii) of the composition with those described in the above-described embodiment.

[0142] In summary, although not limiting, the following embodiments 1 to 35 of the present invention can be considered as further embodiments.

[0143] 1. At least the following steps: (a) A step of introducing a material to be pyrolyzed, which includes at least a material containing a mixture of a polycarbonate-containing compound and a polystyrene-containing compound, into a reactor, (b) A step of decomposing at least the material to be thermally decomposed introduced into the reactor in step (a) at a temperature of 300°C to 700°C to obtain a gaseous product as a thermal decomposition product and a non-gas phase thermal decomposition residue, (i) During decomposition, the amount of oxygen gas in the reactor is 2.0% by volume or less relative to the total volume of gases present in the reactor, and (ii) During decomposition, the thermal decomposition products are discharged from the reactor, (iii) A process for discharging the pyrolysis residue from the reactor, (c) A step of cooling the discharged pyrolysis product to a temperature of less than 300°C to obtain a pyrolysis product selected from pyrolysis product condensate, pyrolysis product sublimation, or a mixture thereof, (d) A step of optionally treating the pyrolysis product, A thermal decomposition process that includes this process.

[0144] 2. The process according to Embodiment 1, wherein the reactor is selected from a continuous stirring tank reactor (CSTR), a fixed bed reactor, a fluidized bed reactor, a screw reactor, a screw conveyor reactor, a jet reactor, a jet reactor, a rotary tube reactor, a fluidized bed reactor, and a drum reactor, and in particular, is selected from a continuous stirring tank reactor (CSTR), a fixed bed reactor (in particular, a continuous bed exchange type with an internal heat exchanger (shaft reactor)), a screw reactor, a screw conveyor reactor, a jet reactor, a rotary tube reactor, or a fluidized bed reactor.

[0145] 3. The process according to embodiment 1 or 2, characterized in that the temperature in step (b) is 350°C to 650°C, preferably 400°C to 650°C, particularly preferably 420°C to 600°C, and very particularly preferably 450°C to 580°C.

[0146] 4. The process according to any one of the above embodiments, characterized in that the temperature of the introduced material to be pyrolyzed is controlled to 300°C to 700°C, and once this target temperature is reached, the residence time of the temperature-controlled material to be pyrolyzed until the time for discharge of the pyrolysis residue generated from the material is set to 1 second to 2 hours, preferably 2 minutes to 60 minutes.

[0147] 5. The process according to any one of the above embodiments, characterized in that the discharge of pyrolysis products from the reactor is ensured by a gas flow passing through the reactor or by suction, and preferably by setting the residence time of the pyrolysis products, which is the time between the introduction time of the material introduced into the reactor in step (a) and the discharge time of the obtained pyrolysis products, to 0.1 seconds to 10 seconds, preferably 0.5 seconds to 5 seconds, more preferably 0.5 seconds to 2 seconds.

[0148] 6. The process according to any one of the above embodiments, characterized in that the discharge of pyrolysis products from the reactor is ensured by a gas flow passing through the reactor, and the flow rate of the gas flow in the reactor as an empty tower velocity is in the range of 0.01 m / sec to 20 m / sec.

[0149] 7. The process according to any one of the above embodiments, characterized in that the thermal decomposition products in the reactor are in the gas phase.

[0150] 8. The process according to any one of the above embodiments, characterized in that the thermal decomposition residue in the reactor is solid.

[0151] 9. The process according to any one of the above embodiments, characterized in that at least step (a) and step (b) are performed simultaneously in the context of continuous process control.

[0152] 10. The process according to any one of the above embodiments, characterized in that the amount of oxygen gas in the reactor in step (b) is 0.5% by volume or less, preferably 0.1% by volume or less, relative to the total volume of gas present in the reactor.

[0153] 11. The process according to any one of the above embodiments, characterized in that the reactor filled with the above materials is filled with an inert gas, particularly nitrogen, argon, CO2, NO, or a mixture thereof.

[0154] 12. The process according to embodiment 11, characterized in that the inert gas may be further mixed with a reactive gas other than oxygen gas, particularly a gas selected from methane, gaseous H2O, hydrogen gas, or a mixture thereof.

[0155] 13. The polycarbonate-containing compound contains at least 10 * -OC(=O)-O- * (In the formula, * The process according to any one of the above embodiments, characterized in that it is at least one compound containing a structural unit (where represents the valency of the polymer main chain).

[0156] 14. Polystyrene-containing compounds containing at least 10 formulas: * -CR 1 Ph-CH2- * (In the formula, * R represents the valency of the repeating unit of the polymer backbone. 1 The process according to any one of the above embodiments, characterized in that the polymer contains at least one repeating unit of (where 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 (particularly chlorine)).

[0157] 15. The process according to any one of the above embodiments, characterized in that the polycarbonate-containing compound is (i) at least one aromatic compound having at least two hydroxyl groups, preferably bisphenol A, and (ii) at least one compound obtained by reacting phosgene or diphenyl carbonate.

[0158] 16. The process according to any one of the above embodiments, characterized in that the material to be pyrolyzed, more specifically the material, contains a phosphorus-containing organic compound in a total amount limited such that the proportion of phosphorus-containing organic compound introduced into the material to be pyrolyzed in a certain total amount is 0% to 0.5% by weight or less of phosphorus, preferably 0% to 0.1% by weight or less of phosphorus, more preferably 0% to 0.05% by weight or less of phosphorus, and particularly preferably 0% to 0.01% by weight or less of phosphorus, relative to the total weight of the material to be pyrolyzed.

[0159] 17. The process according to embodiment 16, characterized in that the phosphorus present in the phosphorus-containing organic compound has a formal oxidation state of +5.

[0160] 18. The process according to embodiment 16 or 17, characterized in that the phosphorus-containing organic compound is at least one compound selected from the group consisting of organic phosphate esters, organic phosphonic acid esters, organic phosphazenes, and phosphonic acid amines, particularly organic phosphate esters and organic phosphonic acid esters.

[0161] 19. A phosphorus-containing organic compound is a compound of at least one general formula (IV): [ka] (In the formula, R 1 , R 2 , R 3 and R 4 Each of these independently comprises optionally halogenated C1-C8 alkyl, alkyl, preferably C1-C4 alkyl and / or halogen, preferably C5 or C6 cycloalkyl, alkyl, preferably C1-C4 alkyl and / or halogen, preferably C6-C, optionally substituted with chlorine or bromine. 20 Cycloalkyl, or alkyl, preferably C1-C4 alkyl and / or halogen, preferably C7-C, optionally substituted with chlorine or bromine. 12 It is Aralkir, n is independently 0 or 1, preferably 1. q is a number between 0 and 30. The process according to any one of embodiments 16 to 18, characterized in that X is selected from a monocyclic or polycyclic aromatic radical having 6 to 30 carbon atoms or a linear or branched aliphatic radical having 2 to 30 carbon atoms, which may be OH substituted and may have up to 8 ether bonds.

[0162] 20. The material to be thermally decomposed in step (a) is At least one polycarbonate-containing compound, The total amount of phosphorus-containing organic compound introduced is limited to such that the proportion of phosphorus-containing organic compound introduced is 0% to 0.5% by weight or less of phosphorus, preferably 0% to 0.1% by weight or less of phosphorus, more preferably 0% to 0.05% by weight or less of phosphorus, and particularly preferably 0% to 0.01% by weight or less of phosphorus, relative to the total weight of the material to be thermally decomposed. Optionally, at least one polystyrene-containing compound, The process according to any one of embodiments 16 to 19, characterized by including the following:

[0163] 21. The process according to any one of the above embodiments, characterized in that the above material is introduced into a reactor in the form of solid particles, particularly in the form of a granular mixture.

[0164] 22. The solid particles of the above material to be introduced into the reactor, more specifically loose solid particles of the granular mixture, have an average diameter of 0.01 mm to 5 cm X 50.3 The process according to embodiment 21, characterized by having (volume average).

[0165] 23. The process according to any one of the above embodiments, characterized in that the material to be thermally decomposed in step (a) also includes at least one filler in addition to the above material.

[0166] 24. The process according to embodiment 23, characterized in that the filler is at least one metal oxide, preferably selected from SiO2, that does not exhibit catalytic activity for the thermal decomposition of polycarbonate.

[0167] 25. The process according to any one of the above embodiments, characterized in that the material to be thermally decomposed in step (a) includes, in addition to the above material, at least one catalyst that affects the decomposition reaction of the above material.

[0168] 26. The catalyst is made from inorganic salts, minerals, metal oxides, mixed oxides, clays, and zeolites. The process according to embodiment 25, characterized in that it is at least one compound selected from the group.

[0169] 27. The process according to embodiment 25 or 26, characterized in that the catalyst is a basic catalyst.

[0170] 28. The process according to any one of embodiments 25 to 27, characterized in that the catalyst is a heterogeneous catalyst.

[0171] 29. The process according to any one of embodiments 1 to 28, characterized in that the material to be pyrolyzed contains the above material in an amount of 10.0% to 80.0% by weight, more preferably 30.0% to 70.0% by weight, relative to the total weight of the material to be pyrolyzed.

[0172] 30. A pyrolysis apparatus for producing pyrolysis products from a material to be pyrolyzed, comprising at least one measuring device for supplying the material to be pyrolyzed, at least one heatable reactor for pyrolysis, and at least one pyrolysis product collector, The above-mentioned pyrolysis-heatable reactor comprises at least one heating element that can be used to control the temperature in the reactor at a temperature of 300°C to 700°C, and 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 reactor are arranged and configured in relation to each other such that the metering device is connected via at least one supply line to the inlet for the material to be pyrolyzed in the pyrolysis-heatable reactor. Preferably, the pyrolysis reactor and the pyrolysis collector are in fluid communication with each other so that gaseous pyrolysis products can be discharged from the pyrolysis product outlet and the discharged pyrolysis products can be introduced into the pyrolysis product collector. At least one pyrolysis product collector can be used to lower the temperature of the pyrolysis products discharged from the reactor to below 300°C within the collector to form pyrolysis product selected from pyrolysis product condensates, pyrolysis product sublimes, or mixtures thereof, and comprises at least one cooling device temperature-controlled to below 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 measuring device for supplying a material to be pyrolyzed, at least one heatable reactor for pyrolysis, and at least one pyrolysis product collector are arranged and configured in relation to each other so that they can operate simultaneously.

[0173] 31. Use of the pyrolysis apparatus according to embodiment 30 for the recovery of an organic compound having at least two hydroxyl groups that can be used in the production of a polycarbonate-containing compound by simultaneous pyrolysis of a polycarbonate-containing compound and a polystyrene-containing compound, and for the simultaneous recovery of styrene used in the production of a polystyrene-containing compound.

[0174] 32. The use according to embodiment 31, characterized in that the pyrolysis apparatus is used to recover bisphenol A used in the production of polycarbonate-containing compounds.

[0175] 33. In all cases, 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 25% to 80% by weight, (ii) At least one aromatic compound having exactly one hydroxyl group in a total amount of more than 1% by weight, preferably phenol, (iii) At least one aromatic compound having at least one vinyl substituent in a total amount of more than 1.5% by weight, preferably styrene or α-methylstyrene, It includes at least, A composition in which a weight percentage is selected from (i) to (iii) within the range of parts by weight such that the total amount of the weight percentage selected from (i) to (iii) and the weight percentage of the other components of the composition are equal to 100% by weight.

[0176] 34. The composition according to embodiment 33, characterized in that it is a thermal decomposition product.

[0177] 35. The composition according to embodiment 34, characterized in that it is a thermal decomposition product obtained in the process described in any one of embodiments 1 to 29. [Modes for carrying out the invention] [Examples]

[0178] Example 1 (Invention): Polycarbonate / AB manufactured by Covestro Deutschland AG (Leverkusen, Germany) The thermal decomposition of S-compound Bayblend™ FC85 (hereinafter referred to as the PC compound) (free of phosphorus-containing organic compounds) was carried out in a fixed-bed reactor at 500°C with N2 aeration. Polycarbonate was introduced into the reactor in five Al₂O₃ crucibles, each containing 2g of polycarbonate. The residence time of the polycarbonate compound was set to 30 minutes. The gas flow rate (empty column velocity) in the reactor was set to 0.07 m / sec. Two condensers were placed downstream of the reactor to separate and recover the liquid component of the obtained thermal decomposition product. The content of the obtained carbonized material in the thermal decomposition residue was determined by measuring the weight of the crucible after thermal decomposition. The gas downstream of the two condensers was characterized by GC. The components of the thermal decomposition product obtained in oil form were determined by GC-FID. This was performed using an Agilent 7890A equipped with a Supelco SPB50 column. For this purpose, the pyrolysis oil was diluted with acetone at a ratio of 1:50 or 1:100.

[0179] Example 2 (not according to this invention): Covestro Deutschland AG's polycarbonate / ABS blend Bayblend (commercial The thermal decomposition of standard FC85 was carried out in a fixed-bed reactor at 800°C with N2 aeration. PC was introduced into the reactor in five Al2O3 crucibles, each containing 2g of PC. The residence time of the PC mixture was 30 minutes. The gas flow rate (empty tower velocity) in the reactor was set to 0.07 m / sec. Two condensers were placed downstream of the reactor to separate and recover the liquid component of the obtained thermal decomposition product. The content of the obtained carbonized material in the thermal decomposition residue was determined by weighing the crucible after thermal decomposition. The gas downstream of the two condensers was characterized by GC. The components of the thermal decomposition product obtained in oil form were determined by GC-FID according to the analytical method described in Example 1.

[0180] [Table 1]

Claims

1. At least the following steps: (a) A step of introducing a material to be pyrolyzed, which includes at least a material containing a mixture of a polycarbonate-containing compound and a polystyrene-containing compound, into a reactor, (b) A step of decomposing at least the material to be thermally decomposed introduced into the reactor in step (a) at a temperature of 300°C to 700°C to obtain a gaseous product as a thermal decomposition product and a non-gas phase thermal decomposition residue, (i) During the decomposition, the amount of oxygen gas in the reactor is 2.0% by volume or less relative to the total volume of gas present in the reactor, (ii) During the decomposition, the thermal decomposition product is discharged from the reactor, (iii) A step of discharging the thermal decomposition residue from the reactor, (c) A step of cooling the discharged pyrolysis product to a temperature of less than 300°C to obtain a pyrolysis product selected from pyrolysis product condensate, pyrolysis product resublimation, or a mixture thereof, (d) A step of optionally treating the pyrolysis product, A thermal decomposition process that includes this process.

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

3. The process according to claim 1 or 2, characterized in that the introduced material to be pyrolyzed is temperature-controlled to 300°C to 700°C, and once this target temperature is reached, the residence time of the temperature-controlled material to be pyrolyzed until the time for discharge of the pyrolysis residue generated from the material is set to 1 second to 2 hours, preferably 2 minutes to 60 minutes.

4. The process according to any one of claims 1 to 3, 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 setting the residence time of the pyrolysis product, which is the time between the introduction time of the material introduced into the reactor in step (a) and the discharge time of the obtained pyrolysis product, to 0.1 seconds to 10 seconds, preferably 0.5 seconds to 5 seconds, more preferably 0.5 seconds to 2 seconds.

5. The process according to any one of claims 1 to 4, characterized in that the discharge of the pyrolysis product from the reactor is ensured by a gas flow passing through the reactor, and the flow rate of the gas flow in the reactor as an empty tower velocity is in the range of 0.01 m / sec to 20 m / sec.

6. The process according to any one of claims 1 to 5, characterized in that at least step (a) and step (b) are performed simultaneously in the context of continuous process control.

7. The process according to any one of claims 1 to 6, characterized in that the amount of oxygen gas in the reactor in step (b) is 0.5% by volume or less, preferably 0.1% by volume or less, relative to the total volume of gas present in the reactor.

8. In the reactor filled with the aforementioned materials, an inert gas, particularly nitrogen, argon, and CO2, is added. ２ The process according to any one of claims 1 to 7, characterized by being filled with NO, or a mixture thereof.

9. The polycarbonate-containing compound comprises at least 10 ＊ -O-C(=O)-O- ＊ (In the formula, ＊ A compound containing at least one structural unit (where represents the valency of the polymer backbone) The process according to any one of claims 1 to 8, characterized in that it is the process described in any one of claims 1 to 8.

10. The polystyrene-containing compound comprises at least 10 formulas: ＊ -CR １ Ph-CH ２ - ＊ (wherein ＊ represents the valence of the repeating unit of the polymer main chain, R １ is a hydrogen atom or a methyl group, and Ph is a phenyl group optionally substituted with at least one group selected from C １ to C ４ alkyl groups and halogen atoms (especially chlorine)), and at least one polymer containing a repeating unit), the process according to any one of claims 1 to 9.

11. The process according to any one of claims 1 to 10, characterized in that the polycarbonate-containing compound is (i) at least one aromatic compound having at least two hydroxyl groups, preferably bisphenol A, and (ii) at least one compound obtained by reacting phosgene or diphenyl carbonate.

12. The process according to any one of claims 1 to 11, characterized in that the material to be pyrolyzed, more specifically the material, contains a phosphorus-containing organic compound in a total amount such that the proportion of the phosphorus-containing organic compound introduced into the material to be pyrolyzed in a certain total amount is 0% to 0.5% by weight or less of phosphorus, preferably 0% to 0.1% by weight or less of phosphorus, more preferably 0% to 0.05% by weight or less of phosphorus, and particularly preferably 0% to 0.01% by weight or less of phosphorus, relative to the total weight of the material to be pyrolyzed.

13. The process according to claim 12, characterized in that the phosphorus present in the phosphorus-containing organic compound has a formal oxidation state of +5.

14. The process according to claim 12 or 13, characterized in that the phosphorus-containing organic compound is at least one compound selected from the group consisting of organic phosphate esters, organic phosphonic acid esters, organic phosphazenes, and phosphonic acid amines, particularly organic phosphate esters and organic phosphonic acid esters.

15. The phosphorus-containing organic compound is a compound of at least one general formula (IV): 【Chemistry 1】 (In the formula, R １ , R ２ , R ３ and R ４ Each of these is an optional 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 Cycloalkyl, or alkyl, preferably C １ ~C ４ C optionally substituted with alkyl and / or halogen, preferably chlorine or bromine. ７ ~C １２ It is Aralkir, n is independently 0 or 1, preferably 1. q is a number between 0 and 30. X may be OH-substituted and may have up to 8 ether bonds, and may be a monocyclic or polycyclic aromatic radical having 6 to 30 carbon atoms or a linear aromatic radical having 2 to 30 carbon atoms. The process according to any one of claims 12 to 14, characterized in that it is selected from (or a branched aliphatic radical).

16. The process according to any one of claims 1 to 15, characterized in that the material is introduced into the reactor in the form of solid particles, particularly in the form of a granular mixture.

17. The process according to any one of claims 1 to 16, characterized in that the material to be pyrolyzed in step (a) also includes at least one filler in addition to the material.

18. The process according to any one of claims 1 to 17, characterized in that the material to be thermally decomposed contains 10.0% to 80.0% by weight, more preferably 30.0% to 70.0% by weight, of the total weight of the material to be thermally decomposed.

19. A pyrolysis apparatus for producing pyrolysis products from a material to be pyrolyzed, comprising at least one measuring device for supplying the material to be pyrolyzed, at least one heatable reactor for pyrolysis, and at least one pyrolysis product collector, The pyrolysis-heatable reactor comprises at least one heating element that can be used to control the temperature in the reactor between 300°C and 700°C, and at least one inlet for the material to be pyrolyzed and at least one separate outlet for the pyrolyzed product. The metering device and the reactor are arranged and configured in relation to each other such that the metering device is connected to the inlet for the material to be pyrolyzed of the pyrolysis-heatable reactor via at least one supply line. Preferably, the pyrolysis reactor and the pyrolysis product collector are in fluid communication with each other so that gaseous pyrolysis products can be discharged from the pyrolysis product outlet and the discharged pyrolysis products can be introduced into the pyrolysis product collector. The at least one pyrolysis product collector comprises at least one temperature-controlled cooling device that can be used within the collector to lower the temperature of the pyrolysis product discharged from the reactor to below 300°C to form pyrolysis product condensates, pyrolysis product sublimes, or mixtures thereof, and at least one container for collecting and discharging the pyrolysis product obtained by cooling. A pyrolysis apparatus characterized in that the at least one measuring device for supplying the material to be pyrolyzed, the at least one heatable reactor for pyrolysis, and the at least one pyrolysis product collector are arranged and configured in relation to each other so that they can operate simultaneously.

20. Use of the pyrolysis apparatus according to claim 19 for the recovery of an organic compound having at least two hydroxyl groups that can be used in the production of a polycarbonate-containing compound by simultaneous pyrolysis of a polycarbonate-containing compound and a polystyrene-containing compound, and for the simultaneous recovery of styrene used in the production of a polystyrene-containing compound.

21. In either 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 25% to 80% by weight, (ii) At least one aromatic compound having exactly one hydroxyl group in a total amount of more than 1% by weight, preferably phenol, (iii) At least one aromatic compound having at least one vinyl substituent in a total amount of more than 1.5% by weight, preferably styrene or α-methylstyrene, It includes at least, A composition in which a weight percentage is selected from the range of parts by weight of (i) to (iii) such that the total amount of the weight percentage selected from (i) to (iii) and the total amount of the weight percentages of other components equals 100% by weight.

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