Process for recycling at least one target polymer from plastic waste containing at least one contaminant

Abstract

The invention relates to a process for recycling at least one target polymer from plastic waste containing at least one contaminant.

Description

[0001] Process for recycling at least one target polymer from plastic waste containing at least one contaminant

[0002] The invention relates to a process for recycling at least one target polymer from plastic waste containing at least one contaminant.

[0003] Thermoplastics are particularly suitable for material recycling and are therefore well-suited materials for a circular economy. A growing number of manufacturing companies are therefore requesting recycled thermoplastics or compounds with a high proportion of post-consumer recyclates. However, plastics from certain industry waste, such as old electrical appliances, end-of-life vehicles, and construction waste, contain substances that hinder recycling. These are substances or impurities that are currently subject to a limit value or completely banned in waste or new products, but were permitted in production in recent years and decades. They are therefore often referred to as legacy additives. This situation particularly complicates the recycling of insulation materials, soft PVC, or plastics from old electrical appliances (WEEE), because these wastes usually containR Phthalic acid esters (PVC) or brominated flame retardants (insulating materials and WEEE), which are now banned or heavily regulated (Wagner and Schlummer, 2020).

[0004] According to the current REACh regulation, phthalate contents above 0.1% are subject to notification and, in practice, are an exclusion criterion for recycling. ABS and PS (HIPS) from WEEE are often treated with brominated flame retardants. According to the current RoHS regulation, the recycling of WEEE plastics with contents above 0.1% is therefore excluded. More critical is the POP regulation's limit of 500 ppm for the sum of all polybrominated diphenyl ethers (PBDEs). EPS insulation materials have been treated with hexabromocyclododecane (HBCD) over the past four decades. HBCD is now subject to the REACh and POP regulations and is no longer permitted in recyclates (the limit according to the POP regulation is 100 ppm).

[0005] These substances are very nonpolar (log Kow > 3), meaning they are poorly soluble in water and cannot be removed by normal cleaning steps in mechanical recycling processes. Furthermore, the slow migration of these contaminants to the plastic particle surface prevents effective cleaning by washing processes.

[0006] One solution to this problem is the use of solvent-based recycling processes that physically dissolve the target plastic, meaning it doesn't attack the macromolecules, and separate it from insoluble waste components. By adding a non-solvent, the polymers can then be precipitated. Contaminated waste additives remain in solution and can be separated from the precipitated polymer.

[0007] State-of-the-art solvent-based recycling processes are capable of substantially reducing the substances during the recycling process. It has been demonstrated that the addition of suitable precipitants to polymer solutions allows for effective depletion of non-polar contaminated waste additives (EP 1 311599 B1, EP 3 575 353 A1). JP 3752101 B2 also describes the separation of flame retardants by precipitation in non-polar solvents. Due to the non-polar nature of the contaminants to be separated, non-polar precipitants were always used, as the mixed medium of solvent and non-polar non-solvent offers good solubility for non-polar substances.

[0008] The use of polar, fully miscible precipitants for the precipitation of polymer solutions has also been described in the literature. Polystyrene solutions in tetrahydrofuran (THF), a water-miscible solvent, are precipitated by adding water to spherical polystyrene particles (Higuchi et al. 2006, https: / / doi.org / 10.1016 / j.colsurfa.2005.10.042). In this case, no depletion effect on legacy additives such as phthalates or flame retardants is reported.

[0009] A mixed form of polar and non-polar precipitation is described in US 2003 / 0119925 A1 and US 7,056,956 B2. The authors disclose the dissolution of PVC in medium-polar solvents (e.g., MEK), followed by polar water precipitation in the presence of a non-polar phase-separating solvent such as hexane, heptane, or octane. No depletion of legacy additives (such as phthalates) is reported for these patents. Rather, it is known that the technical implementation of the patents failed to achieve effective phthalate depletion from soft PVC, which is why the plant was discontinued in 2019.

[0010] A similar procedure, the precipitation of polymer solutions using mixtures of polar and non-polar solvents, is described in EP1311599B1. Although the precipitation conditions result in a substantial separation of old additives from the plastic matrix, the observed separation effect for non-polar contaminants is attributed to the use of non-polar solvents.

[0011] JP 3752101 B2 discloses the separation of flame retardants from polymer solutions by ultrafine filtration. Here, the brominated flame retardant (decaBDE) is not dissolved and can be separated by solid-liquid separation.

[0012] Alternatively or additionally, it is described that a precipitated polymer or a polymer gel can be mixed with an extraction agent, and the extract can be separated along with the contaminants contained therein. Here, too, the extraction agents chosen are nonpolar, since nonpolar contaminants can be separated (EP 2 513 212 A1).

[0013] Despite these diverse technologies for separating contaminated waste additives from the plastic matrix, the presented state of the art has not yet been implemented. In addition to legal issues, technical and economic aspects also play a major role. The precipitation of polymer solutions made of PVC or PS (also HIPS, EPS) or ABS requires large quantities of non-polar precipitants, and this, as well as in the case of complex precipitation approaches (e.g., solvents, co-solvents, and water), inevitably results in complex, cost-intensive solvent preparation, which calls into question the overall economic viability of the processes due to the high energy requirements for thermal recycling / distillation of the large solvent and precipitant flows. Furthermore, the non-polar precipitants used according to the state of the art (e.g.,Alkanes) due to their low flash points place high and cost-intensive demands on plant safety (explosion protection measures) both in terms of investment costs (specially specified equipment) and operating costs (plant operation under inert gas, among other safety measures).

[0014] A further disadvantage of the current state of the art is the observed loss of quality in recycled polymers. The halogenated polymers and / or flame retardant additives degrade under elevated temperature / time exposure, as already occurs under typical extrusion processing conditions (usually between 220 and 300°C). The (usually autocatalytic) molecular degradation and the resulting, predominantly acidic reaction products often result in three negative consequences: First, a loss of molecular weight of the target polymer, e.g., a Mw degradation of over 10%, often even over 20%, is observed, usually in conjunction with thermo-oxidative polymer instabilization, e.g., a drastically reduced OIT value. Second, the acidic reaction products corrode and wear out the high-quality plant equipment. Third, the resulting degradation products contaminate the recyclates, e.g.,in the case of PBDE with highly toxic PBDD / F and thus make reuse of recycled material impossible.

[0015] Based on this, the object of the present invention was to provide a recycling process which, on the one hand, enables an efficient and gentle (i.e., low thermal and mechanical stress, so that no chemical degradation reactions occur) separation of the components and, on the other hand, is simple and economical to carry out.

[0016] This object is achieved by the recycling method having the feature of claim 1 and the polymer recyclate having the features of claim 16. The further dependent claims show advantageous developments.

[0017] According to the invention, a process for recycling at least one target polymer from plastic waste containing at least one contaminant is provided, which process comprises the following steps: a) the plastic waste is treated with at least one solvent or mixtures thereof, the value of which for the hydrogen bond strength ÖH of the Hansen solubility parameter is from 0.1 to 9 MPa 0 ' 5and has a water solubility of a maximum of 20%, in order to selectively dissolve the at least one target polymer. b) the dissolved target polymer is precipitated by adding water and / or aqueous salt solution and / or water-soluble solvents with a value for the hydrogen bond strength ÖH of the Hansen solubility parameter of 6 to 12 MPa°'5 as a precipitant to form a target polymer gel or target polymer particles which have a higher proportion of dry matter compared to the target polymer solution, and c) the at least one precipitated target polymer is mechanically separated from the at least one liquid phase comprising solvent and precipitant in step b).

[0018] The process according to the invention is based on dissolving pollutant-containing polymers in a medium-polar solvent with limited water solubility. After the optional separation of undissolved waste components, for example, by sedimentation, decantation, centrifugation, or filtration, particularly using a sieve, the polymer solution is precipitated with water or an aqueous salt solution. Doses of water up to a level above the solubility limit are possible due to the interaction between the polymer and water. The resulting suspension of precipitation solution (extract) and precipitated polymer is separated, and the extract, which contains some of the contaminants, is removed.

[0019] To further reduce residual amounts of impurities, two options exist: a) The precipitated polymer is redissolved with the solvent and again with water and / or aqueous salt solution and / or water-soluble solvents with a value for the hydrogen bond strength ÖH of the Hansen solubility parameter of 6 to 12 MPa 0 ' 5 b) Alternatively, water and / or aqueous salt solution and / or water-soluble solvents with a hydrogen bond strength 5H of the Hansen solubility parameter of 6 to 12 MPa 0 ' 5 as a precipitant mixed with the precipitated polymer and blended by suitable agitation units.

[0020] In both cases, precipitated polymers are formed, which are separated from the extract.

[0021] Surprisingly, the highly polar precipitation leads to a separation of non-polar contaminants, favored by the small amounts of precipitant required and the low water solubility.

[0022] The process according to the invention is distinguished from the prior art processes by the following advantages: a) A significantly lower amount of precipitant is required in step b): Instead of 150 to 200% precipitant addition relative to the amount of solution according to the prior art processes, the amount of precipitant is reduced to only 10-20% according to the invention. This reduces the mass flows requiring reprocessing and minimizes the energy required for this purpose. b) The low solubility of the precipitant in the solvent enables cost-effective and energy-saving phase separation. Thus, the water-rich precipitant phases can be easily separated from the extracts and, due to their high polarity, are virtually free of contaminants (<100 ppm).They can be reused directly in the process (for subsequent extraction or precipitation steps, particularly preferably in countercurrent), significantly reducing the previously high energy requirements for the operating fluid cycle under the state of the art. c) In this respect, compared to the state of the art (large precipitant requirements are provided via energy-intensive distillation processes), the described reduced precipitant requirement and the phase separation not only save considerable process energy, but also allow the necessary equipment to be implemented more cost-effectively (lower throughputs required) due to the smaller mass flows. d) Increased safety through the use of a precipitant that is non-flammable under operating conditions.e) An optional addition of salt to the precipitant water increases its precipitating power (further minimizing the required precipitant requirement) and leads to an improvement in the phase separation between the precipitant and solvent on the one hand, and between the polymeric precipitate and the liquid phase of solvent and precipitant on the other. f) An optional addition of a basic and / or pH-buffering salt reduces acid formation under time / temperature stress of the recyclate and thus leads to quality improvements (molecular weight retention) and increased thermal stability (improved OIT values).

[0023] It is preferred that between step a) and step b) the at least one dissolved target polymer is mechanically separated from the non-dissolved components of the plastic waste, wherein the mechanical separation is preferably carried out by sedimentation and / or centrifugation and / or decantation and / or filtration, in particular by means of a sieve. In this case, a multi-stage separation of the non-dissolved impurities is preferably carried out, which consists of at least coarse (>1 mm) and fine (1 mm) particles. <x<=lmm) Abtrennung besteht.

[0024] It is particularly preferred that the mechanical separation of precipitated target polymer and liquid phase in step c) is carried out by filtration and / or sedimentation and / or centrifugation and / or by utilizing the different viscosities and / or flow properties of the precipitated target polymer and the separated liquids.

[0025] It is very particularly preferred that in a further step following step c), the mixture of solvent and precipitant is separated by a first phase separation before the further thermal separation by evaporation takes place.

[0026] It is preferred that in a further step d) following step c), the mixture of solvent and precipitant is separated from the at least one target polymer by evaporation, wherein the solvents and precipitants separated by evaporation are preferably separated by phase separation and fed back into the process.

[0027] A preferred embodiment provides that in a further step following step c), the solvent and precipitant are separated from the mixture of solvent, precipitant and at least one contaminant by evaporation, wherein the solvents and precipitants separated by evaporation are preferably separated by phase separation and fed back into the process.According to a further variant, it is preferred that immediately after step b) the precipitated polymer is treated in at least one further process step with the solvent, the solvent mixture and the precipitant water or aqueous salt solution or water-soluble solvents in order to reduce the concentration of the at least one contaminant, wherein preferably the solvent or solvent mixture is added to redissolve the precipitated polymer and is then reprecipitated with water and the liquid phases are separated from the precipitated target polymer and / or the solvent or solvent mixture and water are added in one step and the liquid phases are separated from the precipitated target polymer.

[0028] It is preferred that the precipitation and separation of the liquid phases is carried out several times in succession, wherein the liquids from the precipitation steps are used for precipitation and purification in subsequent process batches, particularly preferably carried out as a countercurrent process.

[0029] Preferably, in a further step, the at least one separated contaminant is recycled. A preferred embodiment provides that the at least one target polymer is selected from the group consisting of

[0030] • Styrene copolymers, in particular acrylonitrile-butadiene-styrene copolymers, styrene-acrylonitrile, polystyrene, HIPS, expanded polystyrene, extruded polystyrene,

[0031] • Polyvinyl chloride,

[0032] • Polyvinyl dichloride,

[0033] • Polyvinyl acetate,

[0034] • Polyvinyl alcohol,

[0035] • Polyvinyl butyrate,

[0036] • Polycarbonates, as well as

[0037] • Mixtures or blends thereof.

[0038] It is preferred that the at least one contaminant is selected from the group • halogenated substances, in particular fluorinated, chlorinated, brominated or mixed-halogenated aromatic hydrocarbons, or aliphatic hydrocarbons, preferably polychlorinated or polybrominated aromatic hydrocarbons,

[0039] • Flame retardants, particularly preferably chlorinated paraffins, brominated flame retardants, in particular polybrominated diphenyl ethers, polybrominated biphenyls, hexabromocyclododecane, tetrabromobisphenol A, brominated styrene-butadiene copolymer (PolyFR) or l,2-bis(2,4,6-tribromophenoxy)ethane,

[0040] • Polycyclic aromatic hydrocarbons, such as PAH,

[0041] • Plasticizer additives, in particular phthalic acid dialkyl esters, phthalic acid alkylaryl esters, citrates, epoxidized soybean oil (ESBO), adipic acid dialkyl esters, 1,2-cyclohexanedicarboxylic acid di-isononyl ester,

[0042] • Stabilizers, in particular organotin compounds, barium stearate, calcium stearate, lead stearate, lead distearate, cadmium stearate, zinc stearate,

[0043] • Antioxidants, especially bisphenol A and derivatives or sterically hindered phenols and

[0044] • Mixtures thereof.

[0045] It is preferred that the solvent has a value for the hydrogen bond strength 5H of the Hansen solubility parameter of maximum 14 MPa 0 ' 5 , preferably from 0 to 9 MPa 0 ' 5 , particularly preferably from 0.1 to 7 MPa 0 ' 5 has.

[0046] Furthermore, it is preferred that the solvent has a water solubility of at most 18%, particularly preferably at most 15% and most preferably at most 10%.

[0047] Preferably, the at least one solvent is selected from the group consisting of cyclic ethers (e.g. tetrahydrofuran), aliphatic (e.g. acetone, methyl ethyl ketone) and cyclic ketones (e.g. cyclohexanone), alkyl, dialkyl esters, basic ester mixtures (e.g. DBE), carbonates (e.g. propylene carbonate, ethylene carbonate, dialkyl carbonates), alkyl acetates (e.g. ethyl acetate), N-alkyl pyrrolidones (e.g. N-ethyl-2-pyrrolidone (NEP), N-methyl-2-pyrrolidone (NMP), terpenes, cymene, styrene, xylene, toluene, terpenes, (poly)alkylated benzenes, benzyl, phenyl or phenol compounds or a mixture of these.

[0048] It is preferred that step a) is carried out at a temperature of 20 to 180°C, preferably from 40 to 120°C, particularly preferably from 60 to 100°C and / or that steps a) to b) are carried out at temperatures below 100°C, particularly preferably below 80°C, and in particular at temperatures below the flash point of the solvents used.

[0049] Preferably, salts, in particular inorganic salts such as sulfates, nitrates, phosphates, carbonates, metal hydroxides, halides or metal oxides are added to the precipitant to increase the precipitating power.

[0050] It is further preferred that the ratio of precipitant to the mixture of target polymer and solvent is a maximum of 33%, particularly preferably a maximum of 20%, further preferably 10% and even more particularly preferably a maximum of 5%.

[0051] The present invention will be explained in more detail with reference to the following examples, without intending to limit it to the specific embodiments shown here.

[0052] Example 1

[0053] Recycling of HBCD-containing EPS

[0054] Expanded polystyrene is dissolved in CreaSolv® FR5 (10%, i.e. 10% polystyrene and 90% CreaSolv® FR5) at room temperature to 80°C. To do this, 60 g of EPS are dissolved in a 1 liter beaker with 540 g of CreaSolv® FR5 while stirring for 60 minutes. By spraying the EPS lumps with a portion of the solvent used, the dissolution process can be accelerated, thus halving the required dissolution time. 60 g of water are added to the dissolved polystyrene as a precipitant while stirring until it visibly precipitates. After the polystyrene has precipitated and a gel has formed, the liquid supernatant is removed. To do this, the viscous gel lump (153 g) is held back using a spatula, and the liquid supernatant is poured off or decanted. The liquid supernatant, consisting of 487 g solvent and 19 g free water phase, is separated into the two liquid phases using a separatory funnel.The HBCD-containing solvent is subjected to a vacuum distillation process to gently separate the solvent and HBCD (without excessive thermal stress, which would otherwise produce undesirable polybrominated reaction products). This yields 2.4 g of HBCD-containing bottoms, which also contains almost 50% residual solvent, as well as PS oligomers and old additives. The purified solvent distillate (465 g) can then be reused for the next batch (re-dissolving EPS) or the subsequent extraction steps (re-dissolving the precipitated EPS gel). The water separated from the separatory funnel separation can be used for further precipitation. This process can be repeated until the desired concentration of HBCD in the polystyrene is reached.

[0055] Example 2

[0056] Recycling of HIPS with brominated flame retardants

[0057] HIPS is dissolved in CreaSolv® FR5 (10%, i.e. 10% HIPS and 90% CreaSolv® FR5) at 80°C. Once the plastic has completely dissolved, water is added as a precipitant. The plastic initially precipitates in flakes and then forms a gel as a sediment. The supernatant, consisting of solvent and water, is separated from the plastic gel by decanting. The supernatant phases, solvent and water, can be separated from one another using a separating funnel. In a distillation step, the brominated flame retardants are separated from the solvent. The solvent can be used again to dissolve the plastic. The separated water can be used again for precipitation. If further brominated flame retardants are to be removed, a mixture of solvent and water in a ratio of 3:1 is added to the plastic gel so that the plastic is again present at 10% in the mixture.The mixture and the plastic gel are stirred at 80°C for 20 minutes. The plastic gel and the mixture are then separated by decantation. The mixture is separated into its phases (water, solvent) using a separatory funnel. The solvent is sent to the distillation stage and separated from the brominated flame retardants. The water can be reused for precipitation. These steps can be repeated until the desired amount of brominated flame retardants is removed.

[0058] Example 3

[0059] Recycling of ABS with brominated flame retardants

[0060] ABS is dissolved in a dibasic ester or propylene carbonate (10%, i.e. 10% ABS and 90% solvent) at 80°C. Water is added to the dissolved plastic so that it precipitates into a gel. The supernatant, consisting of solvent and water, is separated from the gel and the individual phases (water, solvent) are separated from each other in a separating funnel. The solvent is freed of brominated flame retardants in a distillation and can be used to redissolve the plastic. The separated water can be reused for precipitation. If further flame retardants are to be removed, a mixture of solvent and water in a ratio of 1:1 is added to the gel so that the plastic is again present at 10% in the mixture. The mixture of solvent, water and plastic is stirred at 80°C. The plastic is then separated from the mixture.The mixture is separated into its individual phases (solvent, water) using a separatory funnel. The solvent is separated from the brominated flame retardants in a distillation step and can be reused to dissolve the plastic. The water can then be reused for further precipitation. These steps can be repeated until the desired amount of flame retardant has been removed.

[0061] Example 4

[0062] Recycling of PVC containing DEHP

[0063] Soft PVC is dissolved in CreaSolv® FR3 (10%, i.e. 10% soft PVC and 90% CreaSolv® FR3) at 120-130°C. Water is added to the dissolved PVC until the PVC precipitates into a powder. The supernatant is separated from the precipitate using a sieve to separate the polymer from the solvent and precipitant. The solvent mixture is separated into solvent and precipitant using a separating funnel. The solvent is freed from the plasticizer in a distillation process and can be reused to dissolve PVC. If further plasticizer is to be removed, a mixture of solvent and water (20% water to solvent) is added to the precipitated PVC precipitate, which has been separated from the supernatant, so that the PVC is 10% to the solvent-precipitant mixture. The mixture is stirred at 80°C for 10 minutes. The PVC precipitate is then separated again from the mixture. The mixture, consisting of solvent and water, is separated using a separating funnel.The solvent enters the distillation process and is freed from the plasticizer. The water can be reused for precipitation or mixing. This step can be repeated until the desired amount of plasticizer has been removed.

[0064] Example 5

[0065] Recycling of polyFR and HBCD-containing EPS

[0066] Expanded polystyrene is dissolved in CreaSolv® FR5 (10%, i.e., 10% polystyrene and 90% CreaSolv® FR5) at room temperature to 80°C. The sparingly soluble polyFR is separated from the solution by sedimentation or, preferably, by sedimentation under gravity (centrifugation, decanter). Reduction rates well over 95% are achieved in each separation step. Water is then added to the dissolved polystyrene as a precipitant until it visibly precipitates. After the polystyrene has precipitated and a gel has formed, the supernatant is removed. The supernatant, consisting of solvent and water, is separated using a separatory funnel. The HBCD-containing solvent is subjected to a distillation process to separate the solvent and HBCD. The solvent distillate can be reused to dissolve EPS again. The water separated from the separating funnel separation can be used for further precipitation.This can be repeated until the desired concentration of HBCD in the polystyrene is reached.

[0067] All solvents used have flash points above 100°C and are classified in temperature class T2 due to their high ignition temperatures.

Claims

Patent claims Method for recycling at least one target polymer from plastic waste containing at least one contaminant, in which a) the plastic waste is reacted with at least one solvent or mixtures thereof, the value of which for the hydrogen bond strength ÖH of the Hansen solubility parameter is preferably from 0 to 9 MPa 0 - 5 , preferably from 0.1 to 7 MPa 0 - 5 and has a water solubility of at most 50%, preferably at most 20%, in order to selectively dissolve the at least one target polymer, b) the dissolved target polymer is dissolved by adding water or aqueous salt solution or water-soluble solvents with a value for the hydrogen bond strength ÖH of the Hansen solubility parameter of 6 to 12 MPa 0 - 5as a precipitant is precipitated to form a target polymer gel or target polymer particles which have a higher proportion of dry matter compared to the target polymer solution, and c) the at least one precipitated target polymer is mechanically separated from the at least one liquid phase comprising solvent and precipitant in step b). Method according to claim 1, characterized in that between step a) and step b), the at least one dissolved target polymer is mechanically separated from the undissolved components of the plastic waste, wherein the mechanical separation is preferably carried out by means of sedimentation, decanting, centrifugation, filtration, in particular by means of a sieve, or combinations thereof, and / or that the mechanical separation of precipitated target polymer and liquid phase in step c) is carried out by filtration. tion and / or sedimentation and / or centrifugation and / or by utilizing the different viscosities and / or flow properties of the precipitated target polymer and the separated liquids and / or by utilizing the different viscosities and / or flow properties of the precipitated target polymer and the separated liquids. Process according to claim 1 or 2, characterized in that in a further step d) following step c), the mixture of solvent and precipitant is separated from the at least one target polymer by evaporation, wherein the solvents and precipitants separated by evaporation are preferably separated by phase separation and fed back into the process.Process according to claim 1 or 2, characterized in that in a further step following step c), the solvent and precipitant are separated from the mixture of solvent, precipitant and at least one contaminant by evaporation, wherein the solvents and precipitants separated by evaporation are preferably separated by phase separation and fed back into the process. Process according to one of the preceding claims, characterized in that immediately after step b) and / or c), the precipitated polymer is treated in at least one further process step with solvent, the solvent mixture and the precipitant water in order to reduce the concentration of the at least one contaminant, wherein preferably the solvent or solvent mixture is added to redissolve the precipitated polymer and is then reprecipitated with water and the liquid. Phases are separated from the precipitated target polymer and / or the solvent or solvent mixture and water is added in one step and the liquid phases are separated from the precipitated target polymer. Method according to one of the preceding claims, characterized in that the precipitation and separation of the liquid phases is carried out several times in succession, wherein the liquids from the precipitation steps are used for precipitation and purification in subsequent process batches. Method according to one of the preceding claims, characterized in that in a further step the at least one separated contaminant is recycled. Method according to one of the preceding claims, characterized in that the at least one target polymer is selected from the group consisting of • Styrene copolymers, in particular acrylonitrile-butadiene-styrene copolymers, as well as styrene-acrylonitrile, polystyrene, HIPS, expanded polystyrene, extruded polystyrene, • Polyvinyl chloride, • Polyvinyl dichloride, • Polyvinyl acetate, • Polyvinyl alcohol, • Polyvinyl butyrate, • Polycarbonates and • Mixtures or blends thereof. Method according to one of the preceding claims, characterized in that the at least one contaminant is selected from the group • halogenated substances, in particular fluorinated, chlorinated, brominated or mixed-halogenated aromatic hydrocarbons, or aliphatic hydrocarbons, preferably polychlorinated or polybrominated aromatic hydrocarbons, • Flame retardants, particularly preferably chlorinated paraffins, brominated flame retardants, in particular polybrominated diphenyl ethers, polybrominated biphenyls, hexabromocyclododecane, tetrabromobisphenol A, brominated styrene-butadiene copolymer (PolyFR) or l,2-bis(2,4,6-tribromophenoxy)ethane, • Polycyclic aromatic hydrocarbons, such as PAH, • Plasticizer additives, in particular phthalic acid dialkyl esters, phthalic acid alkylaryl esters, citrates, epoxidized soybean oil (ESBO), adipic acid dialkyl esters, 1,2-cyclohexanedicarboxylic acid di-isononyl ester, • Stabilizers, in particular organotin compounds, barium stearate, calcium stearate, lead stearate, lead distearate, cadmium stearate, zinc stearate, • Antioxidants, especially bisphenol A and derivatives or sterically hindered phenols and • Mixtures thereof. Process according to one of the preceding claims, characterized in that the solvent has a value for the hydrogen bond strength ÖH of the Hansen solubility parameter of at most 1 to 6 MPa 0 - 5 , preferably from 2 to 4 MPa 0 - 5 has.

11. Process according to one of the preceding claims, characterized in that the solvent has a water solubility of at most 15%, preferably at most 10%.

12. The process according to any one of the preceding claims, characterized in that the at least one solvent is selected from the group consisting of cyclic ethers (e.g. tetrahydrofuran), aliphatic (e.g. acetone, methyl ethyl ketone) and cyclic ketones (e.g. cyclohexanone), basic ester mixtures (e.g. DBE), carbonates (e.g. propylene carbonate, ethylene carbonate), alkyl acetates (e.g. ethyl acetate), N-alkylpyrrolidones (e.g. N-ethyl-2-pyrrolidone (NEP), N-methyl-2-pyrrolidone), cymene, styrene, water or a mixture of these.

13. Process according to one of the preceding claims, characterized in that step a) is carried out at a temperature of 20 to 180°C, preferably from 40 to 120°C, particularly preferably from 60 to 100°C and / or that steps a) to b) are carried out at temperatures below 100°C, particularly preferably below 80°C, and in particular at temperatures below the flash point of the solvents used.

14. Process according to one of the preceding claims, characterized in that salts, in particular sulfates, nitrates, phosphates, carbonates, metal hydroxides, halides or oxides are added to the precipitating agent to increase the precipitating power.

15. Process according to one of the preceding claims, characterized in that the ratio of precipitant to the mixture of target polymer and solvent is at most 1:5, preferably from 1:7 to 1:

10. Polymer recyclate containing at least one polymer selected from the group consisting of • Styrene copolymers, in particular acrylonitrile-butadiene-styrene copolymers, as well as styrene-acrylonitrile, polystyrene, HIPS, expanded polystyrene, extruded polystyrene, • Polyvinyl chloride, • Polyvinyl dichloride, • Polyvinyl acetate, • Polyvinyl alcohol, • Polyvinyl butyrate, • Polycarbonates and • Mixtures or blends thereof with a contaminant content in the range of 0.5 to 1000 ppm. Polymer recyclate according to claim 16, characterized in that the contaminant content is in the range of 1 to 200 ppm, preferably in the range of 5 to 100 ppm and / or the target polymer content is in the range of 95.0 to 99.99%, preferably from 96.0 to 99.9% and / or the solvent and / or precipitant content is in the range of 1 ppm to 1000 ppm, preferably from 10 ppm to 500 ppm. Polymer recyclate according to one of claims 16 or 17, characterized in that the contaminants are selected from the group consisting of • halogenated substances, in particular fluorinated, chlorinated, brominated or mixed-halogenated aromatic hydrocarbons, or aliphatic hydrocarbons, preferably polychlorinated or polybrominated aromatic hydrocarbons, • Flame retardants, particularly preferably chlorinated paraffins, brominated flame retardants, in particular polybrominated diphenyl ethers, polybrominated biphenyls, hexabromocyclododecane, tetrabromobisphenol A, brominated styrene-butadiene copolymer (PolyFR) or l,2-bis(2,4,6-tribromophenoxy)ethane, • Polycyclic aromatic hydrocarbons, such as PAH, • Plasticizer additives, in particular phthalic acid dialkyl esters, phthalic acid alkylaryl esters, citrates, epoxidized soybean oil (ESBO), adipic acid dialkyl esters, 1,2-cyclohexanedicarboxylic acid di-isononyl ester, • Stabilizers, in particular organotin compounds, barium stearate, calcium stearate, lead stearate, lead distearate, cadmium stearate, zinc stearate, • Antioxidants, especially bisphenol A and derivatives or sterically hindered phenols and • Mixtures thereof.