Separation of polymer blends containing polyesters by solvent-based methods

Abstract

The present invention in a first aspect provides a method for separating a polymer blend comprising (i) a polyester and (ii) one or more components selected from the group consisting of a second polymer, a third polymer and a filler, the second polymer and the third polymer being different from each other and different from the polyester of (i), the method comprising: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (b) contacting the polymer blend with a solvent comprising gamma-valerolactone at a temperature T1 of less than 170° C., thereby producing a solvent enriched in the dissolved second polymer and a solvent depleted in the second polymer; and and / or (c) contacting the polymer blend provided in (a) or the polymer blend residue obtained in (b) with a solvent comprising gamma-valerolactone at a temperature T2 above 170° C., thereby obtaining a solvent enriched in dissolved polyester and optionally at least a portion of the filler compared to the solvent provided in (a) and a polymer blend residue optionally depleted in polyester and optionally comprising a third polymer and optionally a filler or a portion of the filler. In a second aspect, the invention relates to a polyester obtained or obtainable from the process according to the first aspect. A third aspect of the invention relates to the use of the precipitated polyester obtained or obtainable from the process of the first aspect for textile, fiber, packaging, plastic, automotive, electronic applications. A fourth aspect relates to a process for making products based on polyester obtained or obtainable from the process according to the first aspect.

Description

[Technical field]

[0001] The present invention relates in a first aspect to a method for separating a polymer blend comprising (i) a polyester and (ii) one or more components selected from the group consisting of a second polymer, a third polymer and a filler, the second polymer and the third polymer being different from each other and different from the polyester of (i), the method comprising the steps of: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (b) contacting the polymer blend with the solvent comprising gamma-valerolactone at a temperature T1 of less than 170° C., thereby producing a solvent rich in the dissolved second polymer and ... filler, the process comprising the steps of: and obtaining a polymer blend residue comprising the polyester, optionally a third polymer and optionally a filler; and / or in step (c) contacting the polymer blend provided in (a) or the polymer blend residue obtained in (b) with a solvent comprising gamma-valerolactone at a temperature T2 above 170°C, thereby obtaining a solvent enriched in dissolved polyester and optionally comprising at least a portion of the filler compared to the solvent provided in (a), and a polymer blend residue optionally depleted in polyester and optionally comprising a third polymer and optionally a filler or a portion of the filler.

[0002] In a second aspect, the invention relates to a polyester obtained or obtainable from the process according to the first aspect. A third aspect of the invention relates to the use of the precipitated polyester obtained or obtainable from the process of the first aspect for textile, fiber, packaging, plastic, automotive, electronic applications. A fourth aspect relates to a process for making textiles and / or for making cables or automotive parts based on polyester obtained or obtainable from the process according to the first aspect. [Background technology]

[0003] The demand for polymer materials has increased dramatically in recent decades. However, their poor biodegradability generates large amounts of waste plastic, which in Europe is usually incinerated, resulting in the loss of valuable materials and huge amounts of CO2 emissions. 2 are discharged. Landfilling is even less desirable due to their low biodegradability. Polymeric materials are widely used in the packaging sector, for example in beverage or food packaging. Currently, the majority of food and beverages are packaged in plastic bottles and containers made from polymeric materials, including for example polyethylene terephthalate (PET). PET is also the main component material of modern clothing. These materials are usually less biodegradable, but they are also valuable materials, so it is desirable to recover and reuse these plastics. The same applies to polymer blends, including for example polybutylene terephthalate (PBT). They are usually used in the electronic sector for cable applications, for example as insulating sheaths.

[0004] Although recycling processes have been adopted to convert these waste materials into new manufacturing materials, many problems remain associated with the recycling and recovery of polymeric materials. Textiles containing polyester, especially polyethylene terephthalate (PET), are difficult to recycle because they are mixed with other polymers, cotton, colorants, etc. Therefore, mechanical recycling processes cannot be performed in a closed loop without separation from other materials. For other end-of-life sources of PET, contaminants and mixed polymer waste streams often impede mechanical recycling. The same problems exist for polymer blends of other polyesters, especially polybutylene terephthalate (PBT).

[0005] Techniques for recovering polymeric materials include dissolving the polymeric material. WO 2016 / 12755 A1 discloses extracting polyester from packaging, where a first solvent is used to remove colorants and a second solvent is used to dissolve the polyester. Chen et al. (Wenjun Chen, Yuechao Yang, Xue Lan, Baolong Zhang, Xiaogang Zhang and Tiancheng Mu in Green Chem., 2021, 23, 4065) describe a process to dissolve PET and promote alkaline hydrolysis. However, these methods have limited applicability, especially when attempting to recover polyester from a polymer blend that contains each polyester as just one component of multiple other materials. Summary of the Invention [Problem to be solved by the invention]

[0006] The objective underlying the present invention was therefore to provide an improved process which allows a simple separation of the polyester from other materials contained in the polymer blend, which also allows a high recovery of the polyester without impairing the properties associated with the polymer material, such as its number average molecular weight Mn, and which uses non-hazardous solvents. [Means for solving the problem]

[0007] First Aspect - Process - Method for Separating Polymer Blends In a first aspect, the present invention provides a method for producing a composition comprising the steps of: (i) a polyester; (ii) one or more components selected from the group consisting of a second polymer, a third polymer, and a filler, the second polymer and the third polymer being different from each other and different from the polyester of (i); 1. A method for separating a polymer blend comprising: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (b) contacting the polymer blend with a solvent comprising gamma-valerolactone at a temperature T1 below 170° C., thereby obtaining a solvent rich in the dissolved second polymer and a residue of the polymer blend depleted in said second polymer and comprising a polyester, optionally a third polymer and optionally a filler; and / or (c) contacting the polymer blend provided in (a) or the residue of the polymer blend obtained in (b) with a solvent comprising gamma-valerolactone at a temperature T2 above 170° C., thereby obtaining a solvent enriched in dissolved polyester and optionally containing at least a portion of the filler compared to the solvent provided in (a), and optionally a residue of the polymer blend depleted in polyester and optionally containing a third polymer and optionally a filler or a portion of the filler. The present invention relates to a method comprising the steps of:

[0008] Gamma-valerolactone (C 5 H 8 O 2 5-Methyloxolan-2-one (IUPAC: 5-methyloxolan-2-one, abbreviated as GVL) can be obtained from carbohydrate-based biomass, for example, it is easily obtained from sugars, and is therefore a "green" solvent. It has only been described so far as being capable of dissolving a single type of polymeric material at the outermost. Surprisingly, it has now been found that by using a solvent containing GVL in the above-mentioned method for separating a polymer blend containing a polyester, the polyester can be recovered in good yield and purity. Furthermore, not only can the decrease in the weight average molecular weight Mw of the polyester recovered from the polymer blend be prevented, but the number average molecular weight Mn is also increased. If a filler is present, it can be effectively removed, and the decrease in intrinsic viscosity can also be avoided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] "Polymer blend" means a combination of at least one polymer with at least one further component, either another polymer or a filler, which are combined with each other in any suitable form. For example, in the case of at least two polymers, the polymers are intermingled, or one or more polymers are embedded in one or more other polymers, or the polymers are arranged in separate layers, as well as hybrid forms of combinations of these. For example, a polymer blend is a fabric containing polyethylene terephthalate (PET) and spandex, and / or polyamide (PA), and / or natural polymers such as cotton and / or polymers such as viscose. Another example of a polymer blend is a composite in which a filler such as glass fiber is embedded in polybutylene terephthalate (PBT). By "polymer" we mean natural and synthetic polymers, natural polymers being, for example, cotton, cellulose and lignin. Synthetic polymers are, for example, polyolefins such as polyethylene and polypropylene, polyesters, polyurethanes, polyamides, polyethylene glycols, polyethers such as polytetrahydrofuran, and viscose. Examples of "fillers" include glass fibers, carbon fibers, carbon black, inorganic salts (e.g., talc, disodium carbonate), adhesives, thickeners, defoamers, finishing agents (e.g., water repellent / oil repellent / soiling resistant agents, flame retardants, wrinkle inhibitors, biocides), binders, surfactants (e.g., softeners, scouring agents, antistatic agents), desizing agents, bleaching agents, oxidizing agents, ultraviolet screening agents, emulsifiers, fixing agents, cleaning dispersants, and deforming agents. These components are known to those skilled in the art.

[0010] "Contact" in step (b) preferably means immersing at least a portion of the polymer blend in the solvent. Preferably, the polymer blend is at least partially immersed in the solvent such that at least 60%, more preferably at least 70%, more preferably at least 80%, more preferably at least 90%, more preferably at least 95%, more preferably at least 99% of the polymer blend surface is in contact with the solvent, based on the entire surface of the polymer blend, i.e., as 100%. The same applies to "contact" in step (c), i.e., at least a portion of the polymer blend provided in (a) or the residue of the polymer blend obtained in (b) is immersed in the solvent. Preferably, the polymer blend provided in (a) or the residue of the polymer blend obtained in (b) is at least partially immersed in the solvent such that at least 60%, more preferably at least 70%, more preferably at least 80%, more preferably at least 90%, more preferably at least 95%, more preferably at least 99% of the surface of the polymer blend provided in (a) or the residue of the polymer blend obtained in (b) is in contact with the solvent, based on the entire surface of each polymer blend, i.e., as 100%.

[0011] Generally, there are no specific limitations as to the conditions under which the contacting of (b) and / or (c) is carried out, so long as the respective polymers are effectively dissolved.

[0012] In step (b), the second polymer, preferably spandex, is not only dissolved but is also presumably at least partially decomposed, as evidenced, for example, by differential scanning calorimetry (DSC) measurements. The "spandex" is preferably a copolymer of polyurethane and polyethylene glycol and / or polytetrahydrofuran, and more preferably, the spandex is a copolymer of polyurethane and polyethylene glycol or a copolymer of polyurethane and polytetrahydrofuran.

[0013] Step (b) results in not only a reduction in the second polymer, but also in a polymer blend residue comprising the polyester, optionally a third polymer and optionally a filler, with a reduction in the colorant or a part thereof when a colored polyester is used. Similarly, step (c) results in a polyester with a reduction in the colorant when a colored polyester is used, which is especially evident when combined with step (d) described below. The "reduction in colorant" can be determined based on quantitative L*a*b* values, but can also be visually confirmed with the naked eye, except in the case of optical brighteners: the polymer blend provided in (a) is colored, and the polymer blend residue obtained in (b) and / or the polyester precipitated in (d) are lighter in color and / or closer to white, respectively. "Color" includes chromatic and achromatic colors (white, gray, black). This applies in particular to all colorants other than optical brighteners. By reduced colorant is meant, in particular in the case where the colorant is a fluorescent brightener, a reduced intensity of fluorescent radiation (luminescence) emitted by the residue of the polymer blend obtained in (b) and / or the polyester precipitated in (d) is meant, in comparison with the intensity of the fluorescent radiation (luminescence) emitted by irradiating the polymer blend provided in (a) with light of a wavelength in the range of 250 to 400 nm, preferably in the range of 400 to 600 nm. Methods for measuring the intensity of the emitted fluorescent radiation are known to the person skilled in the art and can be carried out, for example, visually with a UV lamp, by fluorescence measurement or by determining the quantum yield.

[0014] "Reduction of colorant" in terms of L*a*b* values ​​means the following, regardless of whether the colorant is visible to the human eye or is an optical brightener: The absolute value of a* preferably changes by at least 0.2, and / or preferably The absolute value of b* preferably changes by at least 0.2, and / or preferably the L* value is preferably increased by at least 4, These are compared with the L*a*b* values ​​of the pigmented polymer blends presented in (a), respectively, the L*a*b* values ​​being determined according to DIN 5033 and DIN EN ISO 11664-1.6.

[0015] In some preferred embodiments, the colorant is selected from the group consisting of dyes and optical brighteners and mixtures of dyes and optical brighteners. A "colorant" is a substance that changes the color impression of a material. It includes dyes that absorb wavelengths in the visible light (400-780 nm) interval and optical brighteners that amplify the luminescence of a material through absorption of UV light and emission of visible light (through fluorescence). That is, optical brighteners convert radiation that is invisible to the human eye (<400 nm) into fluorescent radiation in the visible blue-red spectral range (400-600 nm). Colorants that can be used or are used to change the color impression of a polymeric material are known to the skilled person. In the context of the present invention, the term "dye" means any type of dye, such as dyes, pigments, dispersions, for example one or more selected from the group consisting of acid dyes, basic dyes, direct dyes, disperse dyes, azo dyes, food dyes, solvent dyes, organic dyes, inorganic dyes, organic pigments, inorganic dyes, dispersion inks, reactive inks, oxidation dyes, reactive dyes, sulfur dyes, mordant dyes and vat dyes. The term "optical brightener" encompasses optical brightening agents, fluorescent brightening agents, and fluorescent whitening agents.

[0016] “Dyes and Pigments” Metin Acikyildiz, Cuebra Guenes, Ahmet Guerses Springer, 2016 (ISBN3:103:1939 Industry); Organic Pigments-Klaus Hunger,Thomas Heber,Martin U.Schmidt,Friedrich Reisinger,Stefan Wanne Wiley-VCH,4th edition,2018(ISBN:978-3-527-32608-2); Encyclopedia of Color,Dyes,Pigments-Volume 1,Gerhard Pfaff,de Gruyter,2021(ISBN:311058588X);Heinrich Zollinger:Color Chemistry:Syntheses,Properties and Applications of Organic Dyes and Pigments.3rd edition.WILEY-VCH Verlag,Weinheim 2003(ISBN:3-906390-2330-Klaus Industry); Dyes:Chemistry,Properties,Applications.WILEY-VCH Verlag,Weinheim 2003(ISBN:3-662-01950-7);Hermann Rath:Lehrbuch der Textilchemieeinschl.der textilchemischen Technologie.2nd edition.Springer-Verlag,Berlin,Heidelberg 1963(ISBN:978-3-662-00065-6);Wilfried Kratzert,Rasmus Peichert:Farbstoffe.Quelle&Meyer,Heidelberg 1981(ISBN:3-494-01021-8);Ullmann's Encyclopedia of industrial chemistry, Wiley-VCH, 2000, sections “dyes and pigments” and “dyes, general survey” (ISBN: 9783527303854). .

[0017] In some preferred embodiments of the method for separating a polymer blend, (b) comprises (b.1) contacting the polymer blend with a solvent comprising gamma-valerolactone at a temperature T1 below 170°C, thereby obtaining a solvent rich in a dissolved second polymer and a polymer blend residue depleted in said second polymer and comprising a polyester, optionally a third polymer and optionally a filler; (b.2) Separating the solvent enriched in the dissolved second polymer obtained in (b.1) and the polymer blend residue, preferably by physical separation methods, thereby obtaining a separated solvent enriched in the dissolved second polymer compared to the solvent provided in (a) and a polymer blend residue depleted in said second polymer and comprising the polyester. Includes.

[0018] The separation of (b.2) is carried out by methods and means known to the person skilled in the art, in particular by solid-liquid separation methods such as filtration, for example hot pressure filtration, sedimentation or centrifugation (see Handbuch der mechanischen Fest-Fluessig-Trennung Taschenbuch-29.April 2004 von Klaus Luckert (Herausgeber)). If colorants are present in the polymer blend, in particular in the polyester, at least a portion remains in the separated solvent obtained in (b.2).

[0019] In some preferred embodiments of the method for separating a polymer blend, (c) comprises (c.1) contacting the polymer blend provided in (a) or the residue of the polymer blend obtained in (b) or (b.2) with a solvent comprising gamma-valerolactone and having a temperature T1a less than or equal to T2 (T2 being a temperature greater than 170° C.), thereby obtaining a mixture comprising the polymer blend and the solvent; (c.2) heating the mixture obtained in (c.1) by continuous heating to a temperature T2 above 170°C, preferably maintaining T2, the heating from T1a to T2 being preferably carried out at a heating rate in the range of 20K / h to 1000K / h, 25K / h to 900K / h, 30K / h to 800K / h, 40K / h to 700K / h, 60K / h to 600K / h, the heating and preferably maintaining, thereby obtaining a solvent enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a part of the filler, and optionally a polymer blend residue depleted in polyester and comprising a third polymer and optionally a filler or a part of the filler, (c.3) optionally separating the dissolved polyester-rich solvent obtained in (c.2) from the polymer blend residue, preferably by hot filtration, more preferably at a temperature T3 in the range of T2-20°C to T2+20°C (T3=T2±20°C), more preferably at a temperature T3 in the range of T2-10°C to T2+10°C (T3=T2±10°C); Includes.

[0020] The expressions "(optionally) at least a part of the filler" and "(optionally) a filler or a part of the filler" in (c.2) mean that, if in the polymer blend provided in (a) a filler soluble in the solvent containing gamma-valerolactone at temperature T2 is present, said soluble filler is also dissolved in the dissolved polyester-rich solvent obtained in (c.2). If in the polymer blend provided in (a) a filler insoluble in the solvent containing gamma-valerolactone at temperature T2 is (also) present, other than (in addition to) a soluble filler, said insoluble filler remains in the polymer blend residue, which is reduced in polyester and optionally contains a third polymer. If the only filler contained in the polymer blend provided in (a) is a filler soluble in the solvent containing gamma-valerolactone at temperature T2, no filler remains in the polymer blend residue. If the polymer blend provided in (a) contains only fillers that are insoluble in the solvent comprising gamma-valerolactone at temperature T2, the fillers all remain in the polymer blend residue. If the polymer blend provided in (a) contains fillers that are insoluble in the solvent comprising gamma-valerolactone at temperature T2 and fillers that are soluble in the solvent comprising gamma-valerolactone at temperature T2, at least a portion of the fillers, i.e. the soluble fillers, are contained in the dissolved polyester-rich solvent obtained in (c.2), and a portion of the fillers, i.e. the insoluble fillers, are contained in the polymer blend residue that is reduced in polyester and optionally comprises a third polymer.

[0021] In hot filtration, the solution, the filter and the funnel are heated, preferably each heated to a temperature of T3. Other means and methods, such as non-heated filtration, for carrying out the separation in (c.3) are known to those skilled in the art. In some embodiments, it is preferred that the hot filtration is carried out under a pressure of 1 bar or more, more preferably in the range of 1 bar to 30 bar, preferably in the range of 1 to 10 bar, more preferably in the range of 1 to 6 bar (hot pressure filtration).

[0022] The temperature T1a shown in (c.1) and (c.2) is the temperature of the solvent containing gamma-valerolactone used in (c.1). T1a is equal to T2, i.e., T1a is either greater than 170°C or T1a is less than T2, for example, T1a is less than 120°C, or T1a is in the range of 120°C to less than T2, preferably greater than 120°C to less than T2. ​​When T1a is T2, the heating in step (c.2) using continuous heating means that the heating is performed so that T2 is maintained, and preferably the heating is adjusted not to exceed a temperature 10°C higher than T2.

[0023] In some preferred embodiments, the polymer blend residue obtained in (c.3) still contains a residual amount of polyester. Thus, preferably, in step (c.4), the polymer blend residue obtained in (c.3) containing a residual amount of polyester is contacted with a solvent containing gamma-valerolactone, preferably at a temperature T3 as defined above, followed by filtration, preferably hot filtration at a temperature T3 as defined above, thereby obtaining a polymer blend residue further depleted in polyester and containing a third polymer and optionally a filler or a part of the filler, and a solvent containing a residual amount of polyester. Preferably, the contacting in (c.4) is carried out such that the polymer blend residue obtained in (c.3) remaining on the filter is now contacted with a solvent containing gamma-valerolactone, especially when hot filtration is used in (c.3), and the solvent containing a residual amount of polyester obtained in (c.4) is separated by filtration. In some preferred embodiments, the remaining amount of polyester-containing solvent obtained in (c.4) is combined with the dissolved polyester-rich solvent obtained in (c.3). In some preferred embodiments in which further steps (d), and / or (e), and / or (f), and / or (g) are performed, which are described in more detail below, the remaining amount of polyester-containing solvent obtained in (c.4) and the amount of precipitated polyester finally obtained from the dissolved polyester-rich solvent obtained in (c.3) are combined.

[0024] In some preferred embodiments of the method for separating polymer blends, when T1a is less than 120°C, the heating is preferably carried out by continuous heating at a heating rate in the range of 20K / h to 1000K / h, 25K / h to 900K / h, 30K / h to 800K / h, 40K / h to 700K / h, 60K / h to 600K / h, preferably the heating is carried out such that the mixture obtained in (c.1) is at a temperature range of 110 to 130°C for less than 60 minutes, preferably less than 50 minutes, more preferably less than 40 minutes, more preferably less than 30 minutes, more preferably less than 20 minutes, or when T1a is more than 120°C, the heating is preferably carried out by continuous heating at a heating rate in the range of 0.1 to 1000K / h, more preferably in the range of 5 to 500K / h, more preferably in the range of 25 to 300K / h.

[0025] In some preferred embodiments, the method of separating a polymer blend comprises: (d) cooling the solvent obtained in (c) or (c.3), enriched in dissolved polyester compared to the solvent provided in (a) and optionally containing at least a portion of the filler, to a temperature below 170°C, preferably below 150°C, more preferably below 140°C, more preferably below 100°C, thereby obtaining precipitated polyester and a solvent reduced in dissolved polyester and optionally containing at least a portion of the filler. Includes.

[0026] The solvent obtained in (c) or (c.2) or (c.3), rich in dissolved polyester compared to the solvent provided in (a) and optionally containing at least a portion of the filler, is preferably cooled in (d) without the addition of anti-solvent, i.e. the solvent obtained in (c) or (c.2) or (c.3) is cooled as obtained. Cooling is carried out in any suitable manner, for example by leaving the solvent obtained in (c) or (c.2) or (c.3) under ambient conditions (1013 mbar, room temperature 20-25° C.) or by applying cooling means, for example by cooling slowly in a crystallizer, preferably at a cooling rate in the range of 3-25 K / h, in some preferred embodiments 3-60 K / h, by dropping into a GVL at a temperature below 30° C., by cooling rapidly, preferably at a rate of more than 100 K / h, etc. A “anti-solvent” is a solvent in which the solubility of the polyester at a temperature in the range of 20-25° C. is less than 1 g / kg. In some alternative embodiments, the solvent obtained in (c) or (c.2) or (c.3), which is rich in dissolved polyester compared to the solvent provided in (a) and optionally contains at least a portion of the filler, is preferably cooled in (d) by adding one or more poor solvents.

[0027] In some preferred embodiments, the method of separating a polymer blend comprises: (e) Separating the precipitated polyester obtained in (d) from the solvent in which the dissolved polyester is reduced, thereby obtaining the precipitated polyester and a solvent in which the dissolved polyester is reduced and optionally containing at least a portion of the filler. Includes.

[0028] In some preferred embodiments, the method of separating a polymer blend comprises: (f) optionally washing the precipitated polyester obtained in (e); (g) drying the precipitated polyester obtained in (e) or the washed precipitated polyester obtained in (f). Includes.

[0029] The washing in optional step (f) is preferably carried out with a solvent selected from the group consisting of methanol, ethanol, propanolol, isopropanolol, acetonitrile, ethyl acetate, acetone, water or a mixture of two or more of these solvents. In some embodiments, the washing in optional step (f) is carried out with a solvent selected from the group consisting of methanol, ethanol, propanolol, isopropanolol, acetonitrile, ethyl acetate, acetone, water, GVL or a mixture of two or more of these solvents. The drying in step (g) is preferably carried out under one or more conditions selected from the group consisting of a pressure in the range of 1 to 1013 mbar, a temperature in the range of 50 to 210°C, preferably in the range of 60 to 180°C, more preferably in the range of 80 to 150°C, a drying time in the range of 30 minutes to 24 hours, drying in an atmosphere comprising nitrogen, preferably at least 90% by volume, more preferably at least 95% by volume, more preferably at least 98% by volume of nitrogen. The drying is carried out by one or more methods selected from the group consisting of conductive drying, convective drying and radiation drying.

[0030] The precipitated polyester obtained in (d), (e), (f) and / or (g) is preferably lighter in color than the polymer blend provided in (a), more preferably the precipitated polyester is colorless. The precipitated polyester preferably has a number average molecular weight Mn higher than the polyester contained in the polymer blend and a mass weight average molecular weight Mw equivalent to that of the polyester contained in the polymer blend, i.e. the deviation of the mass weight average molecular weight Mw from the Mw of the polyester contained in the polymer blend is at least -5% by weight and at most +20% by weight, based on the Mw of the polyester contained in the polymer blend, taken as 100% by weight. If a colorant is present in the polymer blend, especially in the polyester, this will at least partially remain in the solvent obtained in (e) where the dissolved polyester is reduced.

[0031] In some preferred embodiments, the method for separating the polymer blend comprises at least partially recycling the separated solvent obtained in (b.2) and / or the separated solvent obtained in (e) to (b) and / or (c), optionally after one or more work-up steps, which are performed to make the solvent of suitable purity for reuse. For example, colorants and / or fillers, if present, are separated from the solvent, preferably by physical separation methods, more preferably by distillation.

[0032] In some preferred embodiments of the method for separating a polymer blend, T1 is a temperature in the range of 110 to less than 170°C, preferably a temperature in the range of 110 to 165°C, more preferably a temperature in the range of 120 to 150°C. In some preferred embodiments of the method for separating a polymer blend, T2 is a temperature in the range of more than 170°C to 200°C, preferably a temperature in the range of 175 to 190°C, more preferably a temperature in the range of 180 to 190°C. In particular, T2 is a temperature within the respective range. That is, in some embodiments, a constant temperature T2 is maintained. That is, in these embodiments, "maintaining T2" also means maintaining approximately one temperature. In some embodiments, the temperature varies within the range of T2 while performing step (c) or while maintaining T2 in step (c.2), respectively.

[0033] In some preferred embodiments of the process for separating a polymer blend, (a), (b), (c) and optionally (d) are carried out under a pressure in the range of 800 to 200,000 hPa.

[0034] In some preferred embodiments of the process for separating polymer blends, the polyester according to (i) is based on at least one polyhydric alcohol and at least one organic dicarboxylic acid. The at least one polyhydric alcohol of the polyester (i) is preferably at least one diol having 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, more preferably the at least one polyhydric alcohol comprises at least 1,4-butanediol or 1,2-ethanediol. The at least one organic dicarboxylic acid of the polyester (i) is preferably selected from the group consisting of terephthalic acid, adipic acid, 2,5-furandicarboxylic acid and mixtures of two or more of these dicarboxylic acids. In some preferred embodiments of the method for separating polymer blends, the polyester according to (i) is based on 1,4-butanediol or 1,2-ethanediol, more preferably the polyester according to (i) is selected from the group consisting of polymers based on 1,4-butanediol and terephthalic acid (polybutylene terephthalate, PBT), polymers based on 1,2-ethanediol and terephthalic acid (polyethylene terephthalate, PET), copolymers of 1,4-butanediol, adipic acid and terephthalic acid (polybutylene adipate terephthalate, PBAT), polymers of 1,2-ethanediol and 2,5-furandicarboxylic acid (polyethylene furanoate, PEF) and mixtures of two or more of these (co)polymers. In some preferred embodiments, the polyester comprises at least PET or PBT.

[0035] In some preferred embodiments of the method for separating a polymer blend, the second polymer is preferably selected from the group consisting of polyurethane (PU), polyethylene glycol (PEG), polytetrahydrofuran (pTHF), mixtures of these polymers and copolymers of these polymers, and the second polymer is more preferably a copolymer of PU and PEG and / or pTHF, more preferably spandex (a copolymer of PU and PEG or PU and pTHF).

[0036] In some preferred embodiments of the method for separating a polymer blend, the third polymer is preferably selected from the group consisting of polyolefins, preferably polyethylene (PE) and polypropylene (PP), polyamide (PA) and viscose, natural polymers, preferably wool or cotton, mixtures of two or more of these polymers and copolymers of two or more of these polymers, the third polymer is preferably selected from PA, wool, cotton, viscose and mixtures of two or more of these polymers. In some embodiments, there are one or more third polymers in the polymer blend. Preferably, there are at least two third polymers selected from PA, wool, cotton, viscose, more preferably a mixture of PA and at least one of wool, cotton and viscose. More preferably, there are two third polymers, which are preferably PA and cotton or viscose.

[0037] In some preferred embodiments of the method for separating a polymer blend, the filler is selected from the group consisting of glass fiber, carbon fiber, carbon black, inorganic salts (e.g., talc, disodium carbonate), adhesives, thickeners, defoamers, finishing agents (e.g., water / oil / stain repellents, flame retardants, wrinkle inhibitors, biocides), binders, surfactants (e.g., softeners, scouring agents, antistatic agents), desizing agents, bleaching agents, oxidizing agents, ultraviolet light blocking agents, emulsifiers, fixing agents, cleaning dispersants, and deformation agents. In an embodiment in which the polyester is PBT, the filler is one or more selected from the group consisting of glass fiber, carbon fiber, carbon black, inorganic salts (e.g., talc, disodium carbonate), adhesives, thickeners, defoamers, finishing agents (e.g., water / oil / stain repellents, flame retardants, wrinkle inhibitors, biocides), binders, surfactants (e.g., softeners, scouring agents, antistatic agents), desizing agents, bleaching agents, oxidizing agents, UV screening agents, emulsifiers, fixing agents, cleaning dispersants, and deforming agents, and preferably the filler is one or more selected from glass fiber, carbon fiber, carbon black, inorganic salts (e.g., talc, Na2CO3). In an embodiment in which the polyester is PET, the filler is one or more selected from the group consisting of glass fiber, carbon fiber, carbon black, inorganic salts (e.g., talc, disodium carbonate), adhesives, thickeners, defoamers, finishing agents (e.g., water / oil / stain repellent, flame retardants, wrinkle inhibitors, biocides), binders, surfactants (e.g., softeners, scouring agents, antistatic agents), desizing agents, bleaching agents, oxidizing agents, UV screening agents, emulsifiers, fixing agents, cleaning dispersants, and deforming agents, and preferably, the filler is one or more selected from the group consisting of adhesives, thickeners, defoamers, finishing agents (e.g., water / oil / stain repellent, flame retardants, wrinkle inhibitors, biocides), binders, surfactants (e.g., softeners, scouring agents, antistatic agents), desizing agents, bleaching agents, oxidizing agents, UV screening agents, emulsifiers, fixing agents, cleaning dispersants, and deforming agents.

[0038] In some preferred embodiments of the methods for separating polymer blends, the contacting in (b) or (b.1) is conducted for a period of at least 5 minutes, preferably in the range of 5 minutes to 10 hours, more preferably in the range of 5 minutes to 5 hours, more preferably in the range of 5 minutes to 4 hours.

[0039] In some preferred embodiments of the method for separating a polymer blend, the contacting in (c) or the maintaining of T2 in (c.2) is performed for a period of at least 0.1 hours, preferably in the range of 1 minute to 10 hours, more preferably in the range of 1 minute to 2 hours, more preferably in the range of 5 minutes to 1 hour, more preferably in the range of 5 to 30 minutes. As mentioned above, T2 is a temperature within the respective range, i.e. in some embodiments, a constant temperature T2 is maintained, i.e. in these embodiments, "maintaining T2" also means that about a temperature is maintained. In some embodiments, the temperature is varied within the range of T2 while performing step (c) or while maintaining T2 in step (c.2), respectively.

[0040] Polyester + Filler In certain preferred embodiments of the method for separating a polymer blend, wherein the polymer blend comprises, and preferably consists of, a polyester and a filler, the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (c) contacting the polymer blend provided in (a) with a solvent comprising gamma-valerolactone at a temperature T2 above 170°C, thereby obtaining a solvent enriched in dissolved polyester compared to the solvent provided in (a) and optionally containing at least a portion of the filler, and a polymer blend residue depleted in polyester and containing a portion of the filler. Includes.

[0041] In this context, a process comprising steps (a) and (c) or (c.1) to (c.3) means that there is no step (b) between (a) and (c), i.e. step (a) is immediately followed by (step) (c). Preferably, the process in this embodiment consists of steps (a) and (c), optionally (c) being a combination of (c.1), (c.2) and (c.3) as described above and also outlined in detail below, optionally followed by subsequent steps such as (d), and / or (e), and / or (f), and / or (g), and / or recycling at least a portion of the solvent to (c). In this embodiment, heating from a temperature below T2 to T2 is performed continuously, whereby the temperature increases linearly over at least a portion of the heating period, in particular at heating rates in the ranges of 20K / h to 1000K / h, 25K / h to 900K / h, 30K / h to 800K / h, 40K / h to 700K / h, 60K / h to 600K / h.

[0042] In some preferred embodiments of the method for separating a polymer blend, where the polymer blend comprises, and preferably consists of, a polyester and a filler, and optionally includes one or more colorants, the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (c.1) contacting the polymer blend provided in(a) with a solvent comprising gamma-valerolactone and having a temperature T1a less than or equal to T2 (T2 being a temperature greater than 170° C.), thereby obtaining a mixture comprising the polymer blend and the solvent; (c.2) heating the mixture obtained in (c.1) by continuous heating to a temperature T2 above 170°C, preferably maintaining T2, the heating from T1a to T2 being preferably carried out at a heating rate in the range of 20K / h to 1000K / h, 25K / h to 900K / h, 30K / h to 800K / h, 40K / h to 700K / h, 60K / h to 600K / h, the heating and preferably maintaining, thereby obtaining a solvent enriched in dissolved polyester compared to the solvent provided in (a) and optionally containing at least a part of the filler, and optionally a residue of a polymer blend, which is depleted in polyester and optionally contains the filler or a part of the filler, (c.3) optionally separating the dissolved polyester-rich solvent obtained in (c.2) from the polymer blend residue, preferably by hot filtration, more preferably at a temperature T3 in the range of T2-20°C to T2+20°C (T3=T2±20°C), more preferably at a temperature T3 in the range of T2-10°C to T2+10°C (T3=T2±10°C), (d) optionally cooling the solvent obtained in (c.3), enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a portion of the filler, to a temperature below 170°C, preferably below 150°C, more preferably below 140°C, more preferably below 100°C, thereby obtaining precipitated polyester and a solvent reduced in dissolved polyester and optionally comprising at least a portion of the filler; (e) optionally separating the precipitated polyester obtained in (d) from the solvent reduced in dissolved polyester and optionally containing at least a portion of the filler, thereby obtaining the precipitated polyester and the solvent reduced in dissolved polyester and optionally containing at least a portion of the filler. Includes.

[0043] As mentioned above, step (c) results in a polyester with reduced colorant when using colored polyester, especially in combination with step (d) as mentioned above. The colorant can be found in the dissolved polyester-rich solvent obtained in (c.2), which remains in the dissolved polyester-reduced solvent obtained in (e) after precipitation in (d) and optionally containing at least a part of the filler. In some preferred embodiments, the polymer blend residue obtained in (c.3) still contains a residual amount of polyester. Thus, preferably, in step (c.4), the polymer blend residue obtained in (c.3) containing a residual amount of polyester is contacted with a solvent containing gamma-valerolactone, preferably at a temperature T3 as defined above, followed by filtration, preferably hot filtration, at a temperature T3 as defined above, thereby obtaining a polymer blend residue further reduced in polyester and containing a third polymer and optionally a filler or a part of the filler, and a solvent containing a residual amount of polyester. Preferably, the contacting in (c.4), especially when hot filtration is used in (c.3), leaves the polymer blend residue obtained in (c.3) on a filter where it is contacted with a solvent containing gamma-valerolactone, and the remaining amount of polyester-containing solvent obtained in (c.4) is separated by filtration. In some preferred embodiments, the remaining amount of polyester-containing solvent obtained in (c.4) is combined with the dissolved polyester-rich solvent obtained in (c.3). In some preferred embodiments where the above further steps (d), and / or (e), and / or (f), and / or (g) are performed, the remaining amount of polyester-containing solvent obtained in (c.4) and the amount of precipitated polyester finally obtained from the dissolved polyester-rich solvent obtained in (c.3) are combined.

[0044] In some preferred embodiments, the method of separating a polymer blend comprises: (f) optionally washing the precipitated polyester obtained in (e); (g) drying the precipitated polyester obtained in (e) or the washed precipitated polyester obtained in (f). Includes.

[0045] The washing in optional step (f) is preferably carried out with a solvent selected from the group consisting of methanol, ethanol, propanolol, isopropanolol, acetonitrile, ethyl acetate, acetone, water or a mixture of two or more of these solvents. In some embodiments, the washing in optional step (f) is preferably carried out with a solvent selected from the group consisting of methanol, ethanol, propanolol, isopropanolol, acetonitrile, ethyl acetate, acetone, water, GVL or a mixture of two or more of these solvents. The drying in step (g) is preferably carried out under one or more conditions selected from the group consisting of a pressure in the range of 1 to 1013 mbar, a temperature in the range of 50 to 210°C, preferably in the range of 60 to 180°C, more preferably in the range of 80 to 150°C, a drying time in the range of 30 minutes to 24 hours, drying in an atmosphere comprising nitrogen, preferably at least 90% by volume, more preferably at least 95% by volume, more preferably at least 98% by volume of nitrogen. The drying is carried out by one or more methods selected from the group consisting of conductive drying, convective drying and radiation drying.

[0046] Polyester + spandex + optional fillers In some preferred embodiments of the method for separating a polymer blend, wherein the polymer blend comprises a polyester, a second polymer, and optionally a filler, preferably consisting of a polyester, a second polymer, and optionally a filler, and optionally including one or more colorants, the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (b) contacting the polymer blend with a solvent comprising gamma-valerolactone at a temperature T1 less than 170° C., thereby obtaining a solvent rich in the dissolved second polymer and a polymer blend residue depleted in said second polymer and comprising a polyester and, optionally, a filler. Includes.

[0047] In this context, a process comprising steps (a) and (b) means that step (c) may be carried out after step (b), which is used to separate the polyester from the filler, if present in the polymer blend. Preferably, the process in this embodiment consists of steps (a) and (b), optionally (b) being a combination of (b.1) and (b.2) above, optionally followed by subsequent steps such as (c), more preferably (c.1), (c.2), (c.3), (d), and / or (e), and / or (f), and / or (g), and / or recycling at least a portion of the solvent to (b) and / or (c).

[0048] In some preferred embodiments of the method for separating a polymer blend, wherein the polymer blend comprises a polyester, a second polymer, and optionally a filler, preferably consisting of a polyester, a second polymer, and optionally a filler, and optionally including one or more colorants, the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (b) contacting the polymer blend with a solvent comprising gamma-valerolactone at a temperature T1 below 170°C, thereby obtaining a solvent rich in the dissolved second polymer and a polymer blend residue depleted in said second polymer and comprising a polyester and, optionally, a filler; (c.1) contacting the polymer blend residue obtained in (b) with a solvent comprising gamma-valerolactone and having a temperature T1a less than or equal to T2 (T2 being a temperature greater than 170° C.), thereby obtaining a mixture comprising the polymer blend and the solvent; (c.2) heating the mixture obtained in (c.1) by continuous heating to a temperature T2 above 170°C, preferably maintaining T2, the heating from T1a to T2 being preferably carried out at a heating rate in the range of 20K / h to 1000K / h, 25K / h to 900K / h, 30K / h to 800K / h, 40K / h to 700K / h, 60K / h to 600K / h, the heating and preferably maintaining, thereby obtaining a solvent enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a part of the filler, and optionally a polymer blend residue depleted in polyester and comprising a third polymer and optionally a filler or a part of the filler, (c.3) optionally separating the dissolved polyester-rich solvent obtained in (c.2) from the polymer blend residue, preferably by hot filtration, more preferably at a temperature T3 in the range of T2-20°C to T2+20°C (T3=T2±20°C), more preferably at a temperature T3 in the range of T2-10°C to T2+10°C (T3=T2±10°C), (d) optionally cooling the solvent obtained in (c.3), enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a portion of the filler, to a temperature below 170°C, preferably below 150°C, more preferably below 140°C, more preferably below 100°C, thereby obtaining precipitated polyester and a solvent reduced in dissolved polyester and optionally comprising at least a portion of the filler; (e) optionally separating the precipitated polyester obtained in (d) from the solvent reduced in dissolved polyester and optionally containing at least a portion of the filler, thereby obtaining the precipitated polyester and the solvent reduced in dissolved polyester and optionally containing at least a portion of the filler. Includes.

[0049] As mentioned above, step (c) as well as step (b) result in a polyester with reduced colorant when using colored polyester, especially when combined with the previously mentioned step (d). The colorant can be found in the dissolved second polymer-rich solvent obtained in (b) and / or in the dissolved polyester-rich solvent obtained in (c.2), which remains in the dissolved polyester-reduced solvent obtained in (e) after precipitation in (d) and optionally containing at least a portion of the filler. In some preferred embodiments, the polymer blend residue obtained in (c.3) still contains a residual amount of polyester. Thus, preferably, in step (c.4), the polymer blend residue containing a residual amount of polyester obtained in (c.3) is contacted with a solvent containing gamma-valerolactone, preferably at a temperature T3 as defined above, followed by filtration, preferably hot filtration, at a temperature T3 as defined above, thereby obtaining a polymer blend residue further depleted in polyester and containing a third polymer and optionally a filler or a part of the filler, and a solvent containing a residual amount of polyester. Preferably, the contacting in (c.4), especially when hot filtration is used in (c.3), leaves the polymer blend residue obtained in (c.3) on a filter, where it is contacted with a solvent containing gamma-valerolactone, and the solvent containing a residual amount of polyester obtained in (c.4) is separated by filtration. In some preferred embodiments, the solvent containing a residual amount of polyester obtained in (c.4) is combined with the dissolved polyester-rich solvent obtained in (c.3). In some preferred embodiments where the above further steps (d), and / or (e), and / or (f), and / or (g) are performed, the remaining amount of polyester-containing solvent obtained in (c.4) and the amount of precipitated polyester finally obtained from the dissolved polyester-rich solvent obtained in (c.3) are combined.

[0050] In some preferred embodiments, the method of separating a polymer blend comprises: (f) optionally washing the precipitated polyester obtained in (e); (g) drying the precipitated polyester obtained in (e) or the washed precipitated polyester obtained in (f). Includes.

[0051] The washing in optional step (f) is preferably carried out with a solvent selected from the group consisting of methanol, ethanol, propanolol, isopropanolol, acetonitrile, ethyl acetate, acetone, water or a mixture of two or more of these solvents. In some embodiments, the washing in optional step (f) is preferably carried out with a solvent selected from the group consisting of methanol, ethanol, propanolol, isopropanolol, acetonitrile, ethyl acetate, acetone, water, GVL or a mixture of two or more of these solvents. The drying in step (g) is preferably carried out under one or more conditions selected from the group consisting of a pressure in the range of 1 to 1013 mbar, a temperature in the range of 50 to 210°C, preferably in the range of 60 to 180°C, more preferably in the range of 80 to 150°C, a drying time in the range of 30 minutes to 24 hours, drying in an atmosphere comprising nitrogen, preferably at least 90% by volume, more preferably at least 95% by volume, more preferably at least 98% by volume of nitrogen. The drying is carried out by one or more methods selected from the group consisting of conductive drying, convective drying and radiation drying.

[0052] Polyester + PA and / or cotton + optional fillers In some preferred embodiments of the method for separating a polymer blend, the polymer blend comprising a polyester, one or more third polymers and optionally a filler, preferably consisting of a polyester, one or more third polymers and optionally a filler, and optionally including one or more colorants, the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (c) contacting the polymer blend provided in (a) with a solvent comprising gamma-valerolactone at a temperature T2 above 170°C, thereby obtaining a solvent enriched in dissolved polyester and optionally containing at least a portion of the filler compared to the solvent provided in (a), and a polymer blend residue depleted in polyester and containing one or more third polymers and optionally the filler or a portion of the filler. Includes.

[0053] In some preferred embodiments of the method for separating a polymer blend, the polymer blend comprising a polyester, one or more third polymers and optionally a filler, preferably consisting of a polyester, one or more third polymers and optionally a filler, and optionally including one or more colorants, the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (c.1) contacting the polymer blend provided in(a) with a solvent comprising gamma-valerolactone and having a temperature T1a less than or equal to T2 (T2 being a temperature greater than 170° C.), thereby obtaining a mixture comprising the polymer blend and the solvent; (c.2) heating the mixture obtained in (c.1) by continuous heating to a temperature T2 above 170°C, preferably maintaining T2, the heating from T1a to T2 being preferably carried out at a heating rate in the range of 20K / h to 1000K / h, 25K / h to 900K / h, 30K / h to 800K / h, 40K / h to 700K / h, 60K / h to 600K / h, the heating and preferably maintaining, thereby obtaining a solvent enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a portion of the filler, and optionally a polymer blend residue depleted in polyester and comprising one or more third polymers and optionally a filler or a portion of the filler, (c.3) optionally separating the dissolved polyester-rich solvent obtained in (c.2) from the polymer blend residue, preferably by hot filtration, more preferably at a temperature T3 in the range of T2-20°C to T2+20°C (T3=T2±20°C), more preferably at a temperature in the range of T2-10°C to T2+10°C (T3=T2±10°C); (d) optionally cooling the solvent obtained in (c.3), which is richer in dissolved polyester compared to the solvent provided in (a), to a temperature below 170°C, preferably below 150°C, more preferably below 140°C, more preferably below 100°C, thereby obtaining precipitated polyester and a solvent having reduced dissolved polyester and optionally containing the filler or a portion of the filler; (e) optionally separating the precipitated polyester obtained in (d) from the solvent in which the dissolved polyester is reduced, thereby obtaining the precipitated polyester and a solvent in which the dissolved polyester is reduced and optionally containing the filler or a portion of the filler. Includes.

[0054] In this context, a process comprising steps (a) and (c) or (c.1) to (c.3) means that there is no step (b) between (a) and (c), i.e. step (a) is immediately followed by (step) (c). Preferably, the process in this embodiment consists of steps (a) and (c), optionally (c) being a combination of (c.1), (c.2) and (c.3), optionally followed by subsequent steps such as (d), and / or (e), and / or (f), and / or (g), and / or recycling at least a portion of the solvent to (c). In this embodiment, the heating from a temperature below T2 to T2 is carried out continuously, whereby the temperature increases linearly over the entire heating period, in particular at heating rates in the range of 20K / h to 1000K / h, 25K / h to 900K / h, 30K / h to 800K / h, 40K / h to 700K / h, 60K / h to 600K / h. In some preferred embodiments, the polymer blend residue obtained in (c.3) still contains a residual amount of polyester. Thus, preferably, in step (c.4), the polymer blend residue obtained in (c.3) containing a residual amount of polyester is contacted with a solvent containing gamma-valerolactone, preferably at a temperature T3 as defined above, followed by filtration, preferably hot filtration, at a temperature T3 as defined above, thereby obtaining a polymer blend residue further reduced in polyester and containing a third polymer and optionally a filler or part of the filler, and a solvent containing a residual amount of polyester. Preferably, the contacting in (c.4), especially when hot filtration is used in (c.3), leaves the polymer blend residue obtained in (c.3) on a filter where it is contacted with the solvent containing gamma-valerolactone, and the remaining amount of polyester-containing solvent obtained in (c.4) is separated by filtration. In some preferred embodiments, the remaining amount of polyester-containing solvent obtained in (c.4) is combined with the dissolved polyester-rich solvent obtained in (c.3).In some preferred embodiments where the above further steps (d), and / or (e), and / or (f), and / or (g) are performed, the remaining amount of polyester-containing solvent obtained in (c.4) and the amount of precipitated polyester finally obtained from the dissolved polyester-rich solvent obtained in (c.3) are combined.

[0055] As mentioned above, step (c) results in a polyester with reduced colorant when using colored polyester, especially when combined with the previously mentioned step (d). The colorant can be found in the dissolved polyester-rich solvent obtained in (c.2), which remains after precipitation in (d) in the dissolved polyester-reduced solvent obtained in (e) and optionally containing at least a portion of the filler.

[0056] In some preferred embodiments, the method of separating a polymer blend comprises: (f) optionally washing the precipitated polyester obtained in (e); (g) drying the precipitated polyester obtained in (e) or the washed precipitated polyester obtained in (f). Includes.

[0057] The washing in optional step (f) is preferably carried out with a solvent selected from the group consisting of methanol, ethanol, propanolol, isopropanolol, acetonitrile, ethyl acetate, acetone, water or a mixture of two or more of these solvents. In some embodiments, the washing in optional step (f) is preferably carried out with a solvent selected from the group consisting of methanol, ethanol, propanolol, isopropanolol, acetonitrile, ethyl acetate, acetone, water, GVL or a mixture of two or more of these solvents. The drying in step (g) is preferably carried out under one or more conditions selected from the group consisting of a pressure in the range of 1 to 1013 mbar, a temperature in the range of 50 to 210°C, preferably in the range of 60 to 180°C, more preferably in the range of 80 to 150°C, a drying time in the range of 30 minutes to 24 hours, drying in an atmosphere comprising nitrogen, preferably at least 90% by volume, more preferably at least 95% by volume, more preferably at least 98% by volume of nitrogen. The drying is carried out by one or more methods selected from the group consisting of conductive drying, convective drying and radiation drying.

[0058] Polyester + Spandex + PA and / or Cotton + Optional Fillers In some preferred embodiments of the method for separating a polymer blend, the polymer blend comprising a polyester, a second polymer, one or more third polymers and optionally a filler, preferably consisting of a polyester, a second polymer, one or more third polymers and optionally a filler, and optionally including one or more colorants, the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (b) contacting the polymer blend with a solvent comprising gamma-valerolactone at a temperature T1 below 170° C., thereby obtaining a solvent rich in the dissolved second polymer and a polymer blend residue depleted in said second polymer and comprising a polyester, one or more third polymers and optionally a filler; and (c) contacting the polymer blend residue obtained in (b) with a solvent comprising gamma-valerolactone at a temperature T2 above 170°C, thereby obtaining a solvent enriched in dissolved polyester and optionally containing at least a portion of the filler compared to the solvent provided in (a), and a polymer blend residue depleted in polyester and containing one or more third polymers and optionally a filler or a portion of the filler. Includes.

[0059] In some preferred embodiments of the method for separating a polymer blend, the polymer blend comprising a polyester, a second polymer, one or more third polymers and optionally a filler, preferably consisting of a polyester, a second polymer, one or more third polymers and optionally a filler, and optionally including one or more colorants, the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (b) contacting the polymer blend with a solvent comprising gamma-valerolactone at a temperature T1 below 170°C, thereby obtaining a solvent rich in the dissolved second polymer and a polymer blend residue depleted in said second polymer and comprising a polyester, one or more third polymers and optionally a filler; (c.1) contacting the residue of the polymer blend obtained in (b) or (b.2) with a solvent comprising gamma-valerolactone and having a temperature T1a less than or equal to T2 (T2 being a temperature greater than 170° C.), thereby obtaining a mixture comprising the polymer blend and the solvent; (c.2) heating the mixture obtained in (c.1) by continuous heating to a temperature T2 above 170°C, preferably maintaining T2, the heating from T1a to T2 being preferably carried out at a heating rate in the range of 20K / h to 1000K / h, 25K / h to 900K / h, 30K / h to 800K / h, 40K / h to 700K / h, 60K / h to 600K / h, the heating and preferably maintaining, thereby obtaining a solvent enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a part of the filler, and optionally a polymer blend residue depleted in polyester and comprising a third polymer and optionally a filler or a part of the filler, (c.3) optionally separating the solvent obtained in (c.2), rich in dissolved polyester and optionally containing at least a portion of the filler, from the polymer blend residue, preferably by hot filtration, more preferably at a temperature T3 in the range of T2-20°C to T2+20°C (T3=T2±20°C), more preferably at a temperature in the range of T2-10°C to T2+10°C (T3=T2±10°C), (d) optionally cooling the solvent obtained in (c.3), enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a portion of the filler, to a temperature below 170°C, preferably below 150°C, more preferably below 140°C, more preferably below 100°C, thereby obtaining precipitated polyester and a solvent reduced in dissolved polyester and optionally comprising at least a portion of the filler; (e) optionally separating the precipitated polyester obtained in (d) from the solvent reduced in dissolved polyester and optionally containing at least a portion of the filler, thereby obtaining the precipitated polyester and the solvent reduced in dissolved polyester and optionally containing at least a portion of the filler. Includes.

[0060] As mentioned above, step (c) as well as step (b) result in a polyester with reduced colorant when using colored polyester, especially when combined with the previously mentioned step (d). The colorant can be found in the dissolved second polymer-rich solvent obtained in (b) and / or in the dissolved polyester-rich solvent obtained in (c.2), which remains in the dissolved polyester-reduced solvent obtained in (e) after precipitation in (d) and optionally containing at least a portion of the filler. In some preferred embodiments, the polymer blend residue obtained in (c.3) still contains a residual amount of polyester. Thus, preferably, in step (c.4), the polymer blend residue containing a residual amount of polyester obtained in (c.3) is contacted with a solvent containing gamma-valerolactone, preferably at a temperature T3 as defined above, followed by filtration, preferably hot filtration, at a temperature T3 as defined above, thereby obtaining a polymer blend residue further depleted in polyester and containing a third polymer and optionally a filler or a part of the filler, and a solvent containing a residual amount of polyester. Preferably, the contacting in (c.4), especially when hot filtration is used in (c.3), leaves the polymer blend residue obtained in (c.3) on a filter, where it is contacted with a solvent containing gamma-valerolactone, and the solvent containing a residual amount of polyester obtained in (c.4) is separated by filtration. In some preferred embodiments, the solvent containing a residual amount of polyester obtained in (c.4) is combined with the dissolved polyester-rich solvent obtained in (c.3). In some preferred embodiments where the above further steps (d), and / or (e), and / or (f), and / or (g) are performed, the remaining amount of polyester-containing solvent obtained in (c.4) and the amount of precipitated polyester finally obtained from the dissolved polyester-rich solvent obtained in (c.3) are combined.

[0061] In some preferred embodiments of the method for separating the polymer blend, at least one of (b) and (c), preferably both (b) and (c), is carried out continuously or discontinuously. According to this embodiment, steps (b) and / or (c) are carried out either in a flow of the solvent containing gamma-valerolactone (continuous) or in a stationary state (discontinuous, batchwise). The contacting is carried out in one or more vessels, for example one or more vessels filled with the colored polymer blend material and a specific flow of the solvent containing gamma-valerolactone is guided through this / these vessels. A preferred example is a stirred vessel, preferably in cascade.

[0062] In some preferred embodiments of the method for separating a polymer blend, at least one of (b) and (c), preferably both (b) and (c), is in a countercurrent mode. According to this embodiment, steps (b) and / or (c) are performed in a countercurrent mode. For example, when the contacting of step (b) is performed in a vessel, the solvent containing gamma-valerolactone enters the vessel from one direction (either the side or the top / bottom) and the colored polymeric material enters the vessel from another direction, preferably the opposite direction. In a preferred configuration in which a vertically oriented vessel is used, the solvent containing gamma-valerolactone enters the vessel from the bottom and the polymeric material enters the vessel from the top.

[0063] Whether (b) and (c), preferably both (b) and (c), are carried out continuously or discontinuously, and whether a co-current or counter-current mode is applied, it is preferred to pre-heat the solvent to the respective temperature (T1, T1a, T2, T3) before contacting it with the polymer blend or the respective residue.

[0064] In some preferred embodiments of the method for separating a polymer blend, at least one of (b) and (c), preferably both (b) and (c), is carried out under mechanical mixing, which preferably comprises one or more methods selected from stirring, blending, and ultrasonication.

[0065] In some preferred embodiments, the method of separating a polymer blend comprises: (f) optionally washing the precipitated polyester obtained in (e); (g) drying the precipitated polyester obtained in (e) or the washed precipitated polyester obtained in (f). Includes.

[0066] The washing in optional step (f) is preferably carried out with a solvent selected from the group consisting of methanol, ethanol, propanolol, isopropanolol, acetonitrile, ethyl acetate, acetone, water or a mixture of two or more of these solvents. In some embodiments, the washing in optional step (f) is preferably carried out with a solvent selected from the group consisting of methanol, ethanol, propanolol, isopropanolol, acetonitrile, ethyl acetate, acetone, water, GVL or a mixture of two or more of these solvents. The drying in step (g) is preferably carried out under one or more conditions selected from the group consisting of a pressure in the range of 1 to 1013 mbar, a temperature in the range of 50 to 210°C, preferably in the range of 60 to 180°C, more preferably in the range of 80 to 150°C, a drying time in the range of 30 minutes to 24 hours, drying in an atmosphere comprising nitrogen, preferably at least 90% by volume, more preferably at least 95% by volume, more preferably at least 98% by volume of nitrogen. The drying is carried out by one or more methods selected from the group consisting of conductive drying, convective drying and radiation drying.

[0067] Solvents containing gamma-valerolactone In some preferred embodiments of the method for separating a polymer blend, the solvent comprising gamma-valerolactone is a mixture of gamma-valerolactone and, optionally, water and a log K OW Preferably, the organic solvent is selected from the group consisting of water, C5-C12 alkanes, aliphatic C1-C10 alcohols, C3-C10 ketones, C2-C10 cyclic ketones, HO-[C1-C10 alkyl-O-] n-H (wherein n is an integer ranging from 2 to 1000), C1-C10 alkyl-O-C3-C10 alkyl ether, C3-C10 cyclic ether optionally substituted with one or more C1-C6 alkyl groups, C6-C10 aromatic hydrocarbon optionally substituted with one or more C1-C6 alkyl groups, C2-C10 aliphatic ester, C8-C11 aromatic ester, C5-C10 cyclic carboxylic acid ester (lactone), C3-C12 amide, preferably R 1 R 2 NC(=O)-R 3 (In the formula, R 1 , R 2 are independently a C1 to C4 alkyl group, and R 3 is selected from the group consisting of a C1 to C9 alkyl group, a C1 to C10 ester group, and a C1 to C6 ether group), a C3 to C6 lactam optionally substituted with one or more substituents selected from a C1 to C6 alkyl group, a C1 to C6 ester group, and a C1 to C6 ether group, and one or more solvents selected from the group consisting of a C5 imidazolidine optionally substituted with one or more C1 to C6 alkyl groups, and a C5 to C7 imidazolidone optionally substituted with one or more C1 to C6 alkyl groups.

[0068] In addition to the preferred solvent, the common logarithm of the octanol / water partition coefficient (logK OW ) is also known to those skilled in the art. The octanol / water partition coefficient K OW is defined as the ratio of the chemical concentration of a given compound in the octanol phase to the chemical concentration of that compound in the aqueous phase in a two-phase system of 1-octanol and water at a temperature of 25°C (298K). The octanol / water partition coefficient K OW Methods for determining the octanol / water partition coefficient K of a given compound are known to those skilled in the art. OWis determined using the shake flask method. It consists of dissolving the compound in a given volume of high purity 1-octanol and deionized water (premixed and conditioned for at least 24 hours) and measuring the concentration of the compound in the 1-octanol and aqueous phases, respectively, by a sufficiently accurate method, preferably UV / VIS spectroscopy. This method is described in the OECD Guideline 107 for the testing of chemicals, adopted on 27 July 1995. KOW values ​​for several substances are known and can be easily found, for example, in the Dortmund Database (DDB, see http: / / www.ddbst.com / ddb-search).

[0069] With regard to suitable solvents, for example, the aliphatic C1-C10 alcohol is preferably a C1-C6 monool, more preferably one or more selected from the group consisting of methanol, ethanol and butanol. The C3-C10 ketone is preferably acetone or methyl ethyl ketone or a mixture of acetone and methyl ethyl ketone. The C2-C10 cyclic ketone is preferably cyclohexanone. The C3-C10 cyclic ether optionally substituted with one or more C1-C3 alkyl groups is preferably tetrahydrofuran or 2-methyltetrahydrofuran or a mixture of tetrahydrofuran and 2-methyltetrahydrofuran. The C6-C10 aromatic hydrocarbon optionally substituted with one or more C1-C3 alkyl groups is preferably one or more selected from the group consisting of benzene, toluene, ethylbenzene, xylene (o or p) and mesitylene. The C1-C10 ester is preferably one or more selected from the group consisting of esters of C1-C6 aliphatic monools and C2-C5 aliphatic acids. The C5-C10 cyclic carboxylic acid ester (lactone) is preferably one or more selected from the group consisting of δ-valerolactone, methylated γ-butyrolactone, ethylated γ-butyrolactone, propylated γ-butyrolactone and β-propiolactone. The C3-C6 lactam optionally substituted with one or more C1-C3 alkyl groups is preferably selected from the group consisting of 2-pyrrolidone, 3-pyrrolidone and a mixture of 2-pyrrolidone, 3-pyrrolidone, each of which is optionally substituted, preferably at the nitrogen atom, with one or more C1-C3 alkyl groups, more preferably N-methyl-2-pyrrolidone. The imidazolidone optionally substituted with one or more C1-C3 alkyl groups is preferably 1,3-dimethyl-2-imidazolidinone.

[0070] In some preferred embodiments of the method for separating a polymer blend, at least 1% by weight of the solvent consists of gamma-valerolactone, more preferably at least 5% by weight, more preferably at least 10% by weight, more preferably at least 20% by weight, more preferably at least 30% by weight, more preferably at least 40% by weight, more preferably at least 50% by weight, more preferably at least 80% by weight, more preferably at least 90% by weight, more preferably at least 95% by weight, and more preferably at least 99% by weight.

[0071] In some preferred embodiments of the process for bleaching, the contacting in (b) and / or (c) is carried out such that the ratio by weight of solvent:polymer blend provided in (a) or residue obtained in (b) is in the range of 1:1 to 100:1, preferably in the range of 1:1 to 10:1.

[0072] In some preferred embodiments of the method for separating polymer blends, the same gamma-valerolactone-containing solvent is used in (b), (b.1), (b.2), (c), (c.1), (c.2), and (c.3).

[0073] Second aspect - polyester obtained or obtainable from the process In a second aspect, the present invention is directed to a polyester obtained or obtainable from a process according to the first aspect, preferably from (d), and / or (e), and / or (f), and / or (g) of the process according to the first aspect.

[0074] Third aspect – Use In a third aspect, the present invention relates to the use of a precipitated polyester obtained or obtainable from (d), and / or (e), and / or (f), and / or (g) by the process of the first aspect or the use of a polyester according to the second aspect, preferably from (d), and / or (e), and / or (f) by the process of the first aspect, preferably where the polyester is selected from PBAT, PEF and PET, preferably PET, for the manufacture of textile applications, fiber applications, packaging applications, plastics applications, automotive applications, electronic applications, preferably food packaging, beverage packaging, clothing, footwear, wire, cable. The precipitated polyester obtained or obtainable from (d), and / or (e), and / or (f), and / or (g) or polyesters according to the second aspect are used for textile applications, fiber applications, packaging applications, plastics applications, more preferably food packaging, beverage packaging, clothing and footwear production, and when the polyester is PBT, the precipitated polyester obtained or obtainable from (d), and / or (e), and / or (f), and / or (g) by the process of the first aspect or polyesters according to the second aspect are used for textile applications, automotive applications, electronic applications, more preferably wire and / or cable production.

[0075] Fourth Aspect - Method of Making the Product A fourth aspect of the invention is a method of making a product, comprising the steps of: (I) providing a polyester of the second aspect; (II) To manufacture textiles, fibers, packaging, plastics, automotive parts, and electronic components from the polyesters provided in (I). The present invention relates to a method comprising the steps of:

[0076] Preferably, a textile, more preferably a food packaging, a beverage packaging, a garment or a footwear, is made with (II), especially when the polyester is selected from PBAT, PEF and PET, more preferably PET. Preferably, a cable is made with (II), especially when the polyester is PBT.

[0077] The cable comprises the polyester and conductors described above. A "conductor" is an electrical conductor or optical waveguide. Electrical conductors are usually made of copper, or more rarely aluminum or a suitable metal alloy. Optical waveguides are constructed from quartz glass fibers.

[0078] The present invention will be further described by the following embodiments and combinations of embodiments shown by their respective dependencies and back references. Specifically, in each instance where a range of embodiments is mentioned in conjunction with a term such as "any one of embodiments 1 to 4", it is meant that any embodiment falling within this range is expressly disclosed to a person skilled in the art, that is, the wording of this term should be understood by a person skilled in the art to be equivalent to "any one of embodiments 1, 2, 3 and 4".

[0079] 1.(i) polyester; (ii) one or more components selected from the group consisting of a second polymer, a third polymer, and a filler, the second polymer and the third polymer being different from each other and different from the polyester of (i); A method for separating a polymer blend comprising: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (b) contacting the polymer blend with a solvent comprising gamma-valerolactone at a temperature T1 below 170° C., thereby obtaining a solvent rich in the dissolved second polymer and a residue of the polymer blend depleted in said second polymer and comprising a polyester, optionally a third polymer and optionally a filler; and / or (c) contacting the polymer blend provided in (a) or the residue of the polymer blend obtained in (b) with a solvent comprising gamma-valerolactone at a temperature T2 above 170° C., thereby obtaining a solvent enriched in dissolved polyester and optionally containing at least a portion of the filler compared to the solvent provided in (a), and optionally a residue of the polymer blend depleted in polyester and optionally containing a third polymer and optionally a filler or a portion of the filler. The method includes:

[0080] 2.(b) is (b.1) contacting the polymer blend with a solvent comprising gamma-valerolactone at a temperature T1 below 170°C, thereby obtaining a solvent rich in a dissolved second polymer and a polymer blend residue depleted in said second polymer and comprising a polyester, optionally a third polymer and optionally a filler; (b.2) Separating the solvent enriched in the dissolved second polymer obtained in (b.1) and the polymer blend residue, preferably by physical separation methods, thereby obtaining a separated solvent enriched in the dissolved second polymer compared to the solvent provided in (a) and a polymer blend residue depleted in said second polymer and comprising the polyester. 2. A method for separating the polymer blend of embodiment 1, comprising:

[0081] 3.(c) is (c.1) contacting the polymer blend provided in (a) or the residue of the polymer blend obtained in (b) or (b.2) with a solvent comprising gamma-valerolactone and having a temperature T1a less than or equal to T2 (T2 being a temperature greater than 170° C.), thereby obtaining a mixture comprising the polymer blend and the solvent; (c.2) heating the mixture obtained in (c.1) by continuous heating to a temperature T2 above 170°C, preferably maintaining T2, the heating from T1a to T2 being preferably carried out at a heating rate in the range of 20K / h to 1000K / h, 25K / h to 900K / h, 30K / h to 800K / h, 40K / h to 700K / h, 60K / h to 600K / h, the heating and preferably maintaining, thereby obtaining a solvent enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a part of the filler, and optionally a polymer blend residue depleted in polyester and comprising a third polymer and optionally a filler or a part of the filler, (c.3) optionally separating the dissolved polyester-rich solvent obtained in (c.2) from the polymer blend residue, preferably by hot filtration, more preferably at a temperature T3 in the range of T2-20°C to T2+20°C (T3=T2±20°C), more preferably at a temperature T3 in the range of T2-10°C to T2+10°C (T3=T2±10°C); and the method preferably comprises: (c.4) contacting the polymer blend residue obtained in (c.3), if it contains a residual amount of polyester, with a solvent containing gamma-valerolactone, preferably at a temperature T3 as defined above, followed by filtration, thereby obtaining a polymer blend residue further depleted in polyester and containing a third polymer and optionally a filler or a portion of the filler, and a solvent containing a residual amount of polyester. 3. The method of separating a polymer blend of embodiment 1 or 2, further comprising:

[0082] 4. The method for separating polymer blends according to embodiment 3, wherein if T1a is less than 120°C, the heating is preferably carried out by continuous heating at a heating rate in the range of 20K / h to 1000K / h, 25K / h to 900K / h, 30K / h to 800K / h, 40K / h to 700K / h, 60K / h to 600K / h, preferably the heating is carried out such that the mixture obtained in (c.1) is at a temperature in the range of 110 to 130°C for less than 60 minutes, preferably less than 50 minutes, more preferably less than 40 minutes, more preferably less than 30 minutes, more preferably less than 20 minutes, or if T1a is more than 120°C, the heating is preferably carried out by continuous heating at a heating rate in the range of 0.1 to 1000K / h, more preferably in the range of 5 to 500K / h, more preferably in the range of 25 to 300K / h.

[0083] 5. (d) Cooling the solvent obtained in (c) or (c.3), enriched in dissolved polyester compared to the solvent provided in (a) and optionally containing at least a portion of the filler, to a temperature below 170°C, preferably below 150°C, more preferably below 140°C, more preferably below 100°C, thereby obtaining precipitated polyester and a solvent reduced in dissolved polyester and optionally containing at least a portion of the filler. 5. A method for separating a polymer blend according to any one of embodiments 1 to 4, comprising:

[0084] 6. (e) Separating the precipitated polyester obtained in (d) from the solvent in which the dissolved polyester is reduced, thereby obtaining the precipitated polyester and a solvent in which the dissolved polyester is reduced and optionally containing at least a portion of the filler. and preferably (f) optionally washing the precipitated polyester obtained in (e); (g) drying the precipitated polyester obtained in (e) or the washed precipitated polyester obtained in (f). 6. The method of separating a polymer blend according to any one of the preceding embodiments, further comprising:

[0085] 7. A method for separating a polymer blend according to any one of the preceding embodiments, comprising at least partially recycling the separated solvent obtained in (b.2) and / or the separated solvent obtained in (e) to (b) and / or (c), optionally after one or more work-up steps.

[0086] 8. The method for separating a polymer blend according to any one of the preceding embodiments 1 to 7, wherein T1 is a temperature in the range of 110 to less than 170°C, preferably a temperature in the range of 110 to 165°C, more preferably a temperature in the range of 120 to 150°C.

[0087] 9. The method for separating a polymer blend according to any one of the first to eighth embodiments, wherein T2 is a temperature in the range of from above 170°C to 200°C, preferably a temperature in the range of from 175 to 190°C, more preferably a temperature in the range of from 180 to 190°C.

[0088] 10. A method for separating a polymer blend according to any one of the preceding embodiments, wherein (a), (b), (c) and optionally (d) are carried out under a pressure in the range of 800 to 200,000 hPa.

[0089] 11. A method for isolating a polymer blend according to any one of the preceding embodiments, wherein the polyester according to (i) is based on at least one polyhydric alcohol and at least one organic dicarboxylic acid.

[0090] 12. The method of separating a polymer blend according to any one of the preceding embodiments, wherein the at least one polyhydric alcohol of the polyester (i) is preferably at least one diol having from 2 to 12 carbon atoms, more preferably from 2 to 6 carbon atoms, and more preferably the at least one polyhydric alcohol comprises at least 1,4-butanediol or 1,2-ethanediol.

[0091] 13. A method for separating a polymer blend according to any one of the preceding embodiments, wherein at least one organic dicarboxylic acid of the polyester (i) is selected from the group consisting of terephthalic acid, adipic acid, 2,5-furandicarboxylic acid and mixtures of two or more of these dicarboxylic acids, preferably at least terephthalic acid.

[0092] 14. Method for separating polymer blends according to any one of the preceding embodiments, wherein the polyester according to (i) is selected from the group consisting of polymers based on 1,4-butanediol and terephthalic acid (polybutylene terephthalate, PBT), polymers based on 1,2-ethanediol and terephthalic acid (polyethylene terephthalate, PET), copolymers of 1,4-butanediol, adipic acid and terephthalic acid (polybutylene adipate terephthalate, PBAT), polymers of 1,2-ethanediol and 2,5-furandicarboxylic acid (polyethylene furanoate, PEF) and (co)polymers of two or more of these, preferably the polyester according to (i) is a polymer of 1,4-butanediol and terephthalic acid (PBT) or a polymer of 1,2-ethanediol and terephthalic acid (PET).

[0093] 15. The method of separating a polymer blend according to any one of the preceding embodiments, wherein the second polymer is preferably selected from the group consisting of polyurethane (PU), polyethylene glycol (PEG), polytetrahydrofuran (pTHF), mixtures of these polymers and copolymers of these polymers, and the second polymer is more preferably a copolymer of PU and PEG and / or pTHF, more preferably spandex (a copolymer of PU and PEG or PU and pTHF).

[0094] 16. The method of separating a polymer blend according to any one of the preceding embodiments, wherein the third polymer is preferably selected from the group consisting of polyolefins, preferably polyethylene (PE) and polypropylene (PP), polyamide (PA) and viscose, natural polymers, preferably wool or cotton, mixtures of two or more of these polymers and copolymers of two or more of these polymers, and the third polymer is preferably selected from PA, wool, cotton, viscose and mixtures of two or more of these polymers.

[0095] 17. The method for separating a polymer blend according to any one of the preceding embodiments, wherein the filler is selected from the group consisting of glass fiber, carbon fiber, carbon black, inorganic salts (e.g., talc, disodium carbonate), adhesives, thickeners, defoamers, finishing agents (e.g., water / oil / stain repellents, flame retardants, wrinkle inhibitors, biocides), binders, surfactants (e.g., softeners, scouring agents, antistatic agents), desizing agents, bleaching agents, oxidizing agents, ultraviolet screening agents, emulsifiers, fixing agents, cleaning dispersants, and deforming agents.

[0096] 18. A method for separating a polymer blend according to any one of the preceding embodiments 1 to 17, wherein the contacting in (b) or (b.1) is carried out for a period of at least 5 minutes, preferably in the range of 5 minutes to 10 hours, more preferably in the range of 5 minutes to 5 hours, more preferably in the range of 5 minutes to 4 hours.

[0097] 19. A method for separating a polymer blend according to any one of embodiments 1 to 18, wherein the contacting in (c) or (c.1) is carried out for a period of at least 0.1 hours, preferably in the range of 1 minute to 10 hours, more preferably in the range of 1 minute to 2 hours, more preferably in the range of 5 minutes to 1 hour, more preferably in the range of 5 to 30 minutes.

[0098] 20. The polymer blend comprises, and preferably consists of, a polyester and a filler, and the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (c) contacting the polymer blend provided in (a) with a solvent comprising gamma-valerolactone at a temperature T2 above 170°C, thereby obtaining a solvent enriched in dissolved polyester and optionally containing at least a portion of the filler compared to the solvent provided in (a), and a polymer blend residue depleted in polyester and containing the filler. 20. A method for separating a polymer blend according to any one of embodiments 1 to 19, comprising:

[0099] 21. The polymer blend comprises, preferably consists of, a polyester and a filler, and optionally comprises one or more colorants, and the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (c.1) contacting the polymer blend provided in(a) with a solvent comprising gamma-valerolactone and having a temperature T1a less than or equal to T2 (T2 being a temperature greater than 170° C.), thereby obtaining a mixture comprising the polymer blend and the solvent; (c.2) heating the mixture obtained in (c.1) by continuous heating to a temperature T2 above 170°C, preferably maintaining T2, the heating from T1a to T2 being preferably carried out at a heating rate in the range of 20K / h to 1000K / h, 25K / h to 900K / h, 30K / h to 800K / h, 40K / h to 700K / h, 60K / h to 600K / h, the heating and preferably maintaining, thereby obtaining a solvent enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a part of the filler, and optionally a polymer blend residue depleted in polyester and comprising a third polymer and optionally a filler or a part of the filler, (c.3) optionally separating the dissolved polyester-rich solvent obtained in (c.2) from the polymer blend residue, preferably by hot filtration, more preferably at a temperature T3 in the range of T2-20°C to T2+20°C (T3=T2±20°C), more preferably at a temperature T3 in the range of T2-10°C to T2+10°C (T3=T2±10°C), (d) optionally cooling the solvent obtained in (c.3), enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a portion of the filler, to a temperature below 170°C, preferably below 150°C, more preferably below 140°C, more preferably below 100°C, thereby obtaining precipitated polyester and a solvent reduced in dissolved polyester and optionally comprising at least a portion of the filler; (e) optionally separating the precipitated polyester obtained in (d) from the solvent reduced in dissolved polyester and optionally containing at least a portion of the filler, thereby obtaining the precipitated polyester and the solvent reduced in dissolved polyester and optionally containing at least a portion of the filler. Preferably, the method for separating the polymer blend comprises: (f) optionally washing the precipitated polyester obtained in (e); (g) drying the precipitated polyester obtained in (e) or the washed precipitated polyester obtained in (f). and / or preferably, the method further comprises: (c.4) contacting the polymer blend residue obtained in (c.3), if it contains a residual amount of polyester, with a solvent containing gamma-valerolactone, preferably at a temperature T3 as defined above, followed by filtration, thereby obtaining a polymer blend residue further depleted in polyester and containing a third polymer and optionally a filler or a portion of the filler, and a solvent containing a residual amount of polyester. 21. The method of any one of embodiments 20 to separate a polymer blend, further comprising:

[0100] 22. The polymer blend comprises a polyester, a second polymer, and optionally a filler, preferably consisting of a polyester, a second polymer, and optionally a filler, and optionally including one or more colorants, and the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (b) contacting the polymer blend with a solvent comprising gamma-valerolactone at a temperature T1 less than 170° C., thereby obtaining a solvent rich in the dissolved second polymer and a polymer blend residue depleted in said second polymer and comprising a polyester and, optionally, a filler. 20. A method for separating a polymer blend according to any one of embodiments 1 to 19, comprising:

[0101] 23. The polymer blend comprises a polyester, a second polymer, and optionally a filler, preferably consisting of a polyester, a second polymer, and optionally a filler, and optionally including one or more colorants, and the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (b) contacting the polymer blend with a solvent comprising gamma-valerolactone at a temperature T1 below 170°C, thereby obtaining a solvent rich in the dissolved second polymer and a polymer blend residue depleted in said second polymer and comprising a polyester and, optionally, a filler; (c.1) contacting the polymer blend residue obtained in (b) with a solvent comprising gamma-valerolactone and having a temperature T1a less than or equal to T2 (T2 being a temperature greater than 170° C.), thereby obtaining a mixture comprising the polymer blend and the solvent; (c.2) heating the mixture obtained in (c.1) by continuous heating to a temperature T2 above 170°C, preferably maintaining T2, the heating from T1a to T2 being preferably carried out at a heating rate in the range of 20K / h to 1000K / h, 25K / h to 900K / h, 30K / h to 800K / h, 40K / h to 700K / h, 60K / h to 600K / h, the heating and preferably maintaining, thereby obtaining a solvent enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a part of the filler, and optionally a polymer blend residue depleted in polyester and comprising a third polymer and optionally a filler or a part of the filler, (c.3) optionally separating the dissolved polyester-rich solvent obtained in (c.2) from the polymer blend residue, preferably by hot filtration, more preferably at a temperature T3 in the range of T2-20°C to T2+20°C (T3=T2±20°C), more preferably at a temperature T3 in the range of T2-10°C to T2+10°C (T3=T2±10°C), (d) optionally cooling the solvent obtained in (c.3), enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a portion of the filler, to a temperature below 170°C, preferably below 150°C, more preferably below 140°C, more preferably below 100°C, thereby obtaining precipitated polyester and a solvent reduced in dissolved polyester and optionally comprising at least a portion of the filler; (e) optionally separating the precipitated polyester obtained in (d) from the solvent reduced in dissolved polyester and optionally containing at least a portion of the filler, thereby obtaining the precipitated polyester and the solvent reduced in dissolved polyester and optionally containing at least a portion of the filler. Preferably, the method for separating the polymer blend comprises: (f) optionally washing the precipitated polyester obtained in (e); (g) drying the precipitated polyester obtained in (e) or the washed precipitated polyester obtained in (f). and / or preferably, the method further comprises: (c.4) contacting the polymer blend residue obtained in (c.3), if it contains a residual amount of polyester, with a solvent containing gamma-valerolactone, preferably at a temperature T3 as defined above, followed by filtration, thereby obtaining a polymer blend residue further depleted in polyester and containing a third polymer and optionally a filler or a portion of the filler, and a solvent containing a residual amount of polyester. 23. The method of separating a polymer blend of embodiment 22, further comprising:

[0102] 24. The polymer blend comprises a polyester, one or more third polymers and optionally a filler, preferably consisting of a polyester, one or more third polymers and optionally a filler, and optionally including one or more colorants, and the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (c) contacting the polymer blend provided in (a) with a solvent comprising gamma-valerolactone at a temperature T2 above 170°C, thereby obtaining a solvent enriched in dissolved polyester and optionally containing at least a portion of the filler compared to the solvent provided in (a), and a polymer blend residue depleted in polyester and containing one or more third polymers and optionally the filler or a portion of the filler. 20. A method for separating a polymer blend according to any one of embodiments 1 to 19, comprising:

[0103] 25. The polymer blend comprises a polyester, one or more third polymers and optionally a filler, preferably consisting of a polyester, one or more third polymers and optionally a filler, and optionally including one or more colorants, and the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (c.1) contacting the polymer blend provided in(a) with a solvent comprising gamma-valerolactone and having a temperature T1a less than or equal to T2 (T2 being a temperature greater than 170° C.), thereby obtaining a mixture comprising the polymer blend and the solvent; (c.2) heating the mixture obtained in (c.1) by continuous heating to a temperature T2 above 170°C, preferably maintaining T2, the heating from T1a to T2 being preferably carried out at a heating rate in the range of 20K / h to 1000K / h, 25K / h to 900K / h, 30K / h to 800K / h, 40K / h to 700K / h, 60K / h to 600K / h, the heating and preferably maintaining, thereby obtaining a solvent enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a portion of the filler, and optionally a polymer blend residue depleted in polyester and comprising one or more third polymers and optionally a filler or a portion of the filler, (c.3) optionally separating the dissolved polyester-rich solvent obtained in (c.2) from the polymer blend residue, preferably by hot filtration, more preferably at a temperature T3 in the range of T2-20°C to T2+20°C (T3=T2±20°C), more preferably at a temperature in the range of T2-10°C to T2+10°C (T3=T2±10°C); (d) optionally cooling the solvent obtained in (c.3), which is richer in dissolved polyester compared to the solvent provided in (a), to a temperature below 170°C, preferably below 150°C, more preferably below 140°C, more preferably below 100°C, thereby obtaining precipitated polyester and a solvent having reduced dissolved polyester and optionally containing the filler or a portion of the filler; (e) optionally separating the precipitated polyester obtained in (d) from the solvent in which the dissolved polyester is reduced, thereby obtaining the precipitated polyester and a solvent in which the dissolved polyester is reduced and optionally containing the filler or a portion of the filler. Preferably, the method for separating the polymer blend comprises: (f) optionally washing the precipitated polyester obtained in (e); (g) drying the precipitated polyester obtained in (e) or the washed precipitated polyester obtained in (f). and / or preferably, the method further comprises: (c.4) contacting the polymer blend residue obtained in (c.3), if it contains a residual amount of polyester, with a solvent containing gamma-valerolactone, preferably at a temperature T3 as defined above, followed by filtration, thereby obtaining a polymer blend residue further depleted in polyester and containing a third polymer and optionally a filler or a portion of the filler, and a solvent containing a residual amount of polyester. 25. The method of separating the polymer blend of embodiment 24, further comprising:

[0104] 26. The polymer blend comprises a polyester, a second polymer, one or more third polymers and optionally a filler, preferably consisting of a polyester, a second polymer, one or more third polymers and optionally a filler, optionally including one or more colorants, and the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (b) contacting the polymer blend with a solvent comprising gamma-valerolactone at a temperature T1 below 170° C., thereby obtaining a solvent rich in the dissolved second polymer and a polymer blend residue depleted in said second polymer and comprising a polyester, one or more third polymers and optionally a filler; and (c) contacting the polymer blend residue obtained in (b) with a solvent comprising gamma-valerolactone at a temperature T2 above 170°C, thereby obtaining a solvent enriched in dissolved polyester and optionally containing at least a portion of the filler compared to the solvent provided in (a), and a polymer blend residue depleted in polyester and containing one or more third polymers and optionally a filler or a portion of the filler. 20. A method for separating a polymer blend of any one of embodiments 1 to 19, comprising:

[0105] 27. The polymer blend comprises a polyester, a second polymer, one or more third polymers and optionally a filler, preferably consisting of a polyester, a second polymer, one or more third polymers and optionally a filler, optionally including one or more colorants, and the method comprises: (a) providing a polymer blend and providing a solvent comprising gamma-valerolactone; (b) contacting the polymer blend with a solvent comprising gamma-valerolactone at a temperature T1 below 170°C, thereby obtaining a solvent rich in the dissolved second polymer and a polymer blend residue depleted in said second polymer and comprising a polyester, one or more third polymers and optionally a filler; (c.1) contacting the residue of the polymer blend obtained in (b) or (b.2) with a solvent comprising gamma-valerolactone and having a temperature T1a less than or equal to T2 (T2 being a temperature greater than 170° C.), thereby obtaining a mixture comprising the polymer blend and the solvent; (c.2) heating the mixture obtained in (c.1) by continuous heating to a temperature T2 above 170°C, preferably maintaining T2, the heating from T1a to T2 being preferably carried out at a heating rate in the range of 20K / h to 1000K / h, 25K / h to 900K / h, 30K / h to 800K / h, 40K / h to 700K / h, 60K / h to 600K / h, the heating and preferably maintaining, thereby obtaining a solvent enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a part of the filler, and optionally a polymer blend residue depleted in polyester and comprising a third polymer and optionally a filler or a part of the filler, (c.3) optionally separating the solvent obtained in (c.2), rich in dissolved polyester and optionally containing at least a portion of the filler, from the polymer blend residue, preferably by hot filtration, more preferably at a temperature T3 in the range of T2-20°C to T2+20°C (T3=T2±20°C), more preferably at a temperature in the range of T2-10°C to T2+10°C (T3=T2±10°C), (d) optionally cooling the solvent obtained in (c.3), enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a portion of the filler, to a temperature below 170°C, preferably below 150°C, more preferably below 140°C, more preferably below 100°C, thereby obtaining precipitated polyester and a solvent reduced in dissolved polyester and optionally comprising at least a portion of the filler; (e) optionally separating the precipitated polyester obtained in (d) from the solvent reduced in dissolved polyester and optionally containing at least a portion of the filler, thereby obtaining the precipitated polyester and the solvent reduced in dissolved polyester and optionally containing at least a portion of the filler. Preferably, the method for separating the polymer blend comprises: (f) optionally washing the precipitated polyester obtained in (e); (g) drying the precipitated polyester obtained in (e) or the washed precipitated polyester obtained in (f). and / or preferably, the method further comprises: (c.4) contacting the polymer blend residue obtained in (c.3), if it contains a residual amount of polyester, with a solvent containing gamma-valerolactone, preferably at a temperature T3 as defined above, followed by filtration, thereby obtaining a polymer blend residue further depleted in polyester and containing a third polymer and optionally a filler or a portion of the filler, and a solvent containing a residual amount of polyester. 27. The method of separating a polymer blend of embodiment 26, further comprising:

[0106] 28. The gamma-valerolactone-containing solvent comprises gamma-valerolactone and, optionally, water and a solvent having a log K in the range of -1.6 to +1.6. OW Preferably, the organic solvent is selected from the group consisting of water, C5-C12 alkanes, aliphatic C1-C10 alcohols, C3-C10 ketones, C2-C10 cyclic ketones, HO-[C1-C10 alkyl-O-] n -H (wherein n is an integer ranging from 2 to 1000), C1-C10 alkyl-O-C3-C10 alkyl ether, C3-C10 cyclic ether optionally substituted with one or more C1-C6 alkyl groups, C6-C10 aromatic hydrocarbon optionally substituted with one or more C1-C6 alkyl groups, C2-C10 aliphatic ester, C8-C11 aromatic ester, C5-C10 cyclic carboxylic acid ester (lactone), C3-C12 amide, preferably R 1 R 2 NC(=O)-R 3 (In the formula, R 1 , R 2 are independently a C1 to C4 alkyl group, and R 3is selected from the group consisting of C1-C9 alkyl groups, C1-C10 ester groups, and C1-C6 ether groups), C3-C6 lactams optionally substituted with one or more substituents selected from C1-C6 alkyl groups, C1-C6 ester groups, and C1-C6 ether groups, and one or more solvents selected from the group consisting of C5 imidazolidines optionally substituted with one or more C1-C6 alkyl groups, C5-C7 imidazolidones optionally substituted with one or more C1-C6 alkyl groups.

[0107] 29. A method for separating a polymer blend according to any one of embodiments 1 to 28, wherein at least 1% by weight of the solvent consists of gamma-valerolactone, more preferably at least 5% by weight, more preferably at least 10% by weight, more preferably at least 20% by weight, more preferably at least 30% by weight, more preferably at least 40% by weight, more preferably at least 50% by weight, more preferably at least 80% by weight, more preferably at least 90% by weight, more preferably at least 95% by weight, more preferably at least 99% by weight.

[0108] 30. A method for separating a polymer blend according to any one of the preceding embodiments, wherein the same gamma-valerolactone-containing solvent is used in (b), (b.1), (b.2), (c), (c.1), (c.2), and (c.3).

[0109] 31. A polyester obtained or obtainable from the method according to any one of embodiments 1 to 30, preferably from (d), and / or (e), and / or (f), and / or (g) according to any one of embodiments 5, 6, 21, 23, 25, and 27.

[0110] 32. Use of the precipitated polyester obtained or obtainable from (d), and / or (e), and / or (f), and / or (g) according to any one of embodiments 5, 6, 21, 23, 25 and 27, or according to embodiment 31, for the manufacture of textile applications, fiber applications, packaging applications, plastic applications, automotive applications, electronic applications, preferably food packaging, beverage packaging, clothing, footwear, wires and cables, preferably where the polyester is selected from PBAT, PEF and PET, preferably PET, and (d), and / or (e), and / or (f) according to any one of embodiments 5, 6, 21, 23, 25 and 27, and The precipitated polyester obtained or obtainable from (d), and / or (e), and / or (f), and / or (g) or the polyester according to embodiment 31 is used for textile applications, fiber applications, packaging applications, plastic applications, more preferably for food packaging, beverage packaging, clothing and footwear production, and when the polyester is PBT, the precipitated polyester obtained or obtainable from (d), and / or (e), and / or (f), and / or (g) or the polyester according to embodiment 31 is used for textile applications, automotive applications, electronic applications, more preferably for wire and / or cable production.

[0111] 33. A method of making a product, comprising: (I) providing a polyester as defined in embodiment 31; (II) To manufacture textiles, fibers, packaging, plastics, automotive parts, and electronic components from the polyesters provided in (I). The method includes:

[0112] The present invention will be further illustrated by the following Reference Examples, Comparative Examples and Examples. EXAMPLES

[0113] method XRF screening analysis (pre / post treatment) The samples were directly subjected to XRF screening without any pretreatment. The sample material was weighed into a measurement cuvette, and the cuvette was placed in the WD-XRF instrument, after which the semi-quantitative program was started. This screening method acts as a rough clustering method to identify the concentration ranges of elements.

[0114] Analysis of Ca, Fe, K, Sb and Ti (before treatment) The samples were pretreated using an automated acid digestion procedure by using a mixture of different mineral acids. The analytes in the resulting solutions were measured by inductively coupled plasma optical emission spectrometry (ICP-OES). Sample pretreatment and analysis were performed in duplicate. The results reported are the average of both individual analytical results.

[0115] Si analysis (before processing) The samples were pretreated by ashing them in a muffle furnace and then decomposing them with a flux. The Si in the resulting solution was measured by inductively coupled plasma optical emission spectrometry (ICP-OES). Sample pretreatment and analysis were performed in duplicate. The reported results are the average of both individual analytical results.

[0116] Cl and S analysis (before treatment) Chlorine (calculated from the sum of Cl, Br, and I) The sample is weighed and placed in a quartz crucible and combusted in oxygen with nitrogen as the carrier gas. The combustion gas by-products are washed with concentrated sulfuric acid and then transferred to a coulometric cell. Detection is performed by coulometric analysis.

[0117] Analysis of Si (for PBT samples) After the samples were ashed in a muffle furnace, an automated flux decomposition procedure was used to pretreat the samples. The Si in the resulting solutions was measured by inductively coupled plasma optical emission spectrometry (ICP-OES). Sample pretreatment and analysis were performed in duplicate. The results reported are the average of both individual analytical results.

[0118] intrinsic viscosity General: To measure the intrinsic viscosity, a concentration series of the polymer is prepared in a particular solvent, here o-chlorophenol. The concentration range of the polymer for analyzing the intrinsic viscosity is determined by the relative viscosity, which should be in the range of 1.2-2.5 [Kulicke 2003].

[0119] The value of intrinsic viscosity is obtained as the intercept point on the y-axis when a graph of reduced viscosity as a function of concentration is extrapolated to a concentration of zero by linear regression.

[0120] Sample preparation and measurements Typically a concentration series is prepared spanning 3-7 different concentrations, the concentration range being determined by the relative viscosity range (see above).

[0121] The polymer is dissolved in o-chlorophenol by stirring overnight. All polymer solutions are filtered through a metal filter with a mesh size of 0.077 mm before use.

[0122] The measurements are carried out at 25° C. in a Lauda apparatus (Lauda Pro Line 24) using an Ubbelohde capillary efflux time viscometer (Micro-Ubbelohde II, k=0.10326, App.Nr.:720-13-0573). The temperature is controlled by a thermostat, which keeps it constant within a range of + / -0.01° C.

[0123] The viscosity of various polymer solutions is determined by measuring the time it takes for the sample to flow through a capillary of defined length and radius under the influence of gravity. To determine the relative viscosity, a measurement is also carried out under the same conditions for a reference solution, here o-chlorophenol. The measured flow time is corrected according to Hagenbach (W.-M. Kulicke and C. Clasen, Viscosimetry of Polymers and Polyelectrolytes, Springer (2003)).

[0124] Hazen Color Number: The Hazen colour index (APHA colour index) was determined according to DIN EN ISO 6271:2016-05 (Pt / Co, APHA, ASTM D1209, D5386).

[0125] CIE-LAB: The samples were measured using an integrating sphere to obtain UV / VIS reflectance spectra (wavelength range 400-700 nm) to determine the L*a*b* values. The data of these spectra were analyzed by the software OptLab-SPX using a standard C illuminant with a standard viewing angle of 2°. The OptLab-SPX software calculates the L*a*b* values ​​according to DIN 5033 and DIN EN ISO 11664-1.6 2007-2014 editions.

[0126] GC area%: The samples were analyzed by gas chromatography (GC), in which the individual components of the samples were detected according to their individual retention times. The concentrations of the individual components in the samples were expressed as a percentage of their peak areas in GC area % units.

[0127] GPC (Gel Permeation Chromatography): Sample preparation: 7.5 mg of sample was dissolved overnight in 5 ml of eluent (HFIP + 0.05 wt% potassium trifluoroacetate). All sample solutions were filtered through Millipore MillexFG (0.2 μm) before injection. The sealed sample vial was placed in the autosampler.

[0128] Test conditions: An Agilent 1100 HPLC system was used, consisting of an isocratic pump, a vacuum degasser, an autosampler, and a column oven (40 °C). In addition, this Agilent system includes a differential refractive index (DRI) and a variable ultraviolet (UVW) detector as detectors. Data acquisition and processing of conventional SEC data were performed on a WinGPC Unichrom from PSS (Polymer Standard Services). An Agilent PL-HFIP guard (7.5 × 50 mm) column was combined with two PL-HFIP gel columns (7.5 × 300 mm, 9 μ) connected in series. Hexafluoroisopropanol + potassium trifluoroacetate 0.05 wt% was used as the eluent at a flow rate of 1 ml / min. 50 μl of each sample solution was injected. Calibration was performed with narrow molar mass distribution PMMA standards (Polymer Standard Services) with molar masses ranging from M = 800 to M = 2,200,000 g / mol. Molar masses outside this range were extrapolated.

[0129] quantitative 1 H NMR spectroscopy (q 1 H NMR): Quantitative analysis of polyethylene terephthalate (PET) and gamma-valerolactone (GVL) content in samples 1 All NMR spectra were measured using a Bruker Avance III 400 spectrometer. 1 For H, the spectrum was operated at 400.33 MHz and recorded at T = 298.2 K. The spectrometer was equipped with a 5 mm z-gradient broadband observe smartprobe. Chemical shifts were referenced to tetramethylsilane (TMS, δ(TMS) = 0 ppm). 1 H 1D spectra were recorded under quantitative conditions using the zg30 pulse program with 128k data points. The relaxation latency D1 was 100 ms for chloroform-d 1 (CDCl 3 ) Select 40 seconds, and the solvent is sulfuric acid-d 2 (D 2 SO4 ), a time of 120 seconds was selected. Eight transients were used per spectrum. For processing with Bruker TopSpin 4.0.9 software, 64k data points and an exponential window function with a line broadening factor of 0.3 Hz were applied. Automatic baseline correction was performed with a polynomial of degree 5, and phase correction and integration were performed manually by the user.

[0130] For PET measurements, the internal standard 1,1,2,2-tetrachloroethane (TCE) and the analyte were accurately weighed (Mettler-Toledo XP205DR analytical balance) into appropriate vials, and then the internal standard was added to CDCl containing a trace amount of TMS. 3 Samples were prepared by dissolving in 2 mL of a 2:1 mixture of 1:1 HCl and trifluoroacetic acid (TFA).

[0131] For the determination of PET in cotton-containing textile samples, the internal standard dimethylmalonic acid (DMMS) and the analyte were accurately weighed (Mettler-Toledo XP205DR analytical balance) into suitable vials, and then the D 2 SO 4 Samples were prepared by dissolving in 2 ml.

[0132] In all cases, samples were transferred to 5 mm NMR tubes for measurement. Deuterated solvents TFA and CDCl 3 and TMS were purchased from Euriso-Top GmbH. 2 SO 4 , TCE and DMMS (certified internal standards) were purchased from Sigma-Aldrich. All solvents and internal standards were used as received.

[0133] The content of the test sample was calculated using the following formula:

number

[0134] Quantitative measurements were performed in triplicate.

[0135] The assessment of PET in pure PET samples was performed using the internal standard TCE with 2 protons / molecule (approximately 5.9 ppm) and the analyte PET with 4 selected protons / molecule (approximately 8.1 ppm).

[0136] The evaluation of PET in the cotton-containing textile samples was performed using an internal standard of DMMS with 6 protons / molecule (approximately 1.80 ppm) and an analyte of PET with 4 protons / molecule (approximately 8.4 ppm).

[0137] [Table 1]

[0138] Reference Example 1a: Regeneration of PET using stepwise heating (Comparative Procedure) The colored PET polymer material (in any color) was cut / shredded into small pieces and charged into a reaction vessel (e.g., flask, test tube, reaction vessel). Degassed gamma-valerolactone (GVL) was added (GVL:polymer material mass ratio 1:1-100:1, preferably 1:1-10:1), and the mixture was heated at 1013 mbar in a suitable heating mechanism (e.g., oil bath, heating block, small plant vessel) first at 120°C for 5-60 minutes, then at 170°C for 1-30 minutes, then at 180°C for 1-30 minutes, and finally at 190°C for 1-30 minutes to obtain a solution. Upon visual inspection, the PET was completely dissolved. The solution was then filtered (e.g., hot pressure filtration). Polyethylene terephthalate (PET) precipitated as the filtrate began to cool. The precipitate was filtered and washed with a small amount of GVL to obtain a faded PET powder. A small amount of acetone was optionally used in a second washing step to facilitate removal of the GVL and again to speed up the drying process of the resulting faded PET powder. The solid thus obtained was dried (e.g., in a vacuum tray dryer).

[0139] Reference Example 1b: Regeneration of PET using continuous heating The colored PET polymer material (in any color) was cut / shredded into small pieces and charged into a reaction vessel (e.g., flask, test tube, reaction vessel). Degassed GVL was added (GVL:polymer material mass ratio 1:1-100:1, preferably 1:1-10:1) and the mixture was heated to 185°C at 1013 mbar in a suitable heating mechanism (e.g., oil bath, heating block, small plant vessel) to obtain a solution. Visual inspection showed that the PET was completely dissolved. After 1-30 minutes, the mixture was filtered (e.g., hot pressure filtration). If there was an insoluble portion of the filler that was insoluble in the GVL, this was retained on the filter. As the filtrate began to cool, the PET precipitated. The precipitate was filtered. If there was a soluble portion of the filler that was soluble in the GVL but did not precipitate on cooling, this was removed together with the filtrate. The precipitated PET was washed with a small amount of GVL. A small amount of acetone was optionally used in a second washing step to facilitate removal of the GVL and again to speed up the drying process of the resulting faded PET powder. The solid thus obtained was dried (e.g., in a vacuum tray dryer).

[0140] Reference Example 2: Separation of PET from cotton and / or PA The colored PET polymeric material (in any color) containing PET and cotton and / or PA was cut / shredded into small pieces and charged into a reaction vessel (e.g., flask, test tube, reaction vessel). Degassed GVL was added (GVL:polymeric material ratio 1:1-100:1, preferably 1:1-10:1 by weight) and the mixture was heated to 185°C at 1013 mbar in a suitable heating mechanism (e.g., oil bath, heating block, small plant vessel) to obtain a mixture. The PET was completely dissolved and the soluble part of the filler, if present, was dissolved in the mixture, while the solid particles remained intact. After 5-30 minutes, the mixture was filtered (e.g., hot pressure filtration), thereby obtaining a filter cake containing the undissolved polymeric material (cotton and / or PA and the insoluble part of the filler, if present) and a filtrate containing PET. The filter cake was optionally washed with a small amount of hot GVL. The PET precipitated out as the filtrate started to cool. The precipitate was filtered. If any part of the filler was present that was soluble in GVL but did not precipitate upon cooling, this was removed together with the filtrate. The precipitated PET was washed with a small amount of GVL. A small amount of acetone was optionally used in a second washing step to facilitate the removal of the GVL and to speed up the drying process of the faded PET powder obtained again. The filter cake was further washed with a small amount of GVL. A small amount of acetone was optionally used in a second washing step to facilitate the removal of the GVL and to speed up the drying process of the cotton of the PA pieces. The polymeric material thus obtained (PET obtained again and undissolved cotton or PA) was dried (e.g. in a vacuum tray dryer).

[0141] Reference Example 3: Separation of Spandex and PET The colored polymeric material (in any color) containing PET and spandex was cut / chopped into small pieces and charged into a reaction vessel (e.g., flask, test tube, reaction vessel). Degassed GVL was added (GVL:polymeric material ratio 1:1-100:1, preferably 1:1-10:1 by weight) and the mixture was heated at 1013 mbar to 110-170°C in a suitable heating mechanism (e.g., oil bath, heating block, small plant vessel) to obtain a mixture in which the spandex was completely dissolved and the PET remained undissolved. If present, part of the filler was also dissolved. After 0.1-4 hours, the mixture was filtered, thereby obtaining spandex and colorant-rich GVL and faded PET pieces, and the polymeric material pieces were washed with a small amount of GVL. A small amount of acetone was optionally used in the second washing step to facilitate the removal of the GVL and to speed up the drying process of the decolorized PET pieces without spandex. The resulting polymeric material crumbs were then dried (eg, in a vacuum tray dryer).

[0142] The following applies to Reference Example 1a and all Reference Examples 1b-4: To reuse the used solvent GVL, the filtrate was optionally distilled (50-200°C, 2 hPa to atmospheric pressure, preferably 70-110°C, 5-30 hPa) to obtain distilled GVL with a purity of more than 99% by area % by GC. The Hazen color number of the GVL was measured before and after distillation. Not only the distilled GVL but also the undistilled GVL could be reused under the same conditions as fresh GVL.

[0143] Reference Example 4: Regeneration of PBT using continuous heating The colored PBT polymer material (in any color) was cut / chopped into small pieces and charged into a reaction vessel (e.g., flask, test tube, reaction vessel). Degassed GVL was added (GVL:polymer material weight ratio 1:1-100:1, preferably 1:1-10:1) and the mixture was heated to 185°C at 1013 mbar in a suitable heating mechanism (e.g., oil bath, heating block, small plant vessel) to obtain a mixture. The PBT was completely dissolved and the soluble portion of the filler, if present, was dissolved in the mixture, while the solid particles remained intact. After 5-30 minutes, the mixture was filtered (e.g., hot pressure filtration), thereby obtaining a filter cake containing the undissolved portion of the filler (e.g., glass fibers) and a filtrate containing the PBT and the dissolved portion of the filler, if present. The filter cake was optionally washed with a small amount of hot GVL. When the filtrate started to cool, the PBT precipitated out. The precipitate was filtered. If present, dissolved portions of the filler that were soluble in GVL but did not precipitate upon cooling were removed together with the filtrate. The precipitated PBT was washed with a small amount of GVL. A small amount of acetone was optionally used in a second washing step to facilitate the removal of the GVL and to speed up the drying process of the faded PBT powder obtained again. The filter cake was further washed with a small amount of GVL. A small amount of acetone was optionally used in a second washing step to facilitate the removal of the GVL and to speed up the drying process of the undissolved filler (e.g., glass fiber). The polymeric material and filler thus obtained (received PBT and undissolved glass fiber) were dried (e.g., in a vacuum tray dryer).

[0144] Examples 1 to 3 (E1 to E3) and Comparative Examples 1 to 4 (C1 to C4): Regeneration of PET The pigmented PET polymeric material was treated as described in Reference Example 1a or Reference Example 1b. The type of polymeric material and the experimental conditions as well as the results are shown in Table 1. Samples before treatment ((pigmented) polymeric material, Table 1) and after the final drying step (regenerated and reobtained discolored solid PET, Table 2) were analyzed to measure the number average molecular weight Mn, the mass average molecular weight Mw, the polydispersity Mw / Mn and quantitative 1H-NMR.

[0145] [Table 2]

[0146] The white fabric had a titanium content of 0.1-1 wt% based on X-ray fluorescence analysis, and the Si, S, Cl, K, Ca, Fe, and Sb contents were each less than 0.1 wt%. The intrinsic viscosity [η] of the white fabric was 0.501 in [100 ml / g].

[0147] [Table 3]

[0148] [Table 4]

[0149] [Table 5]

[0150] It was found that by using the continuous heating procedure according to Reference Example 1b, not only was the decrease in the weight average molecular weight Mw prevented, but the number average molecular weight Mn was also increased.

[0151] X-ray fluorescence results showed that the white fabric of Example E1 had significantly reduced amounts of Si, Ti, and Ni (<0.1%), and other elements such as S, Cl, K, Ca, Fe, and Sb were reduced to below detection limits, demonstrating that the method removed fillers (compared to the starting green fabric). Intrinsic viscosity data obtained for Example E3 showed that the method avoided the loss of intrinsic viscosity (compared to the starting white fabric).

[0152] Examples 4, 5 and 6 (E4, E5, E6): Separation of PET from cotton or PA The pigmented polymeric materials (in any color) were treated as described in Reference Example 2. The types of polymeric materials and the experimental conditions as well as the results are shown in Tables 3 and 4.

[0153] Samples before treatment ((colored) polymeric material, Tables 3 and 4) and after the final drying step (regenerated, re-obtained, faded solid PET and undissolved polymer (cotton or PA), Tables 3 and 4) were analyzed and quantitative 1H-NMR measurements were performed to determine the PET content in case of cotton / PET separation and the PA and PET content in case of PA / PET separation.

[0154] [Table 6]

[0155] [Table 7]

[0156] The separation was shown to work very effectively (complete separation was achieved), in particular the resulting PET was reliably free of PA or cotton residues (E4, PET>98%) and almost all of the PET contained in the starting material (at least 98%) could be recovered.

[0157] Example 7 (E7): Separation of Spandex and PET The pigmented polymeric materials (in any color) were processed as described in Reference Example 3. The type of polymeric material and the experimental conditions and the results are shown in Table 5. Samples before processing ((pigmented) polymeric materials, Table 5) and after the final drying step (polymeric materials with reduced colorant and spandex, Table 5) were analyzed and quantitative 1H-NMR measurements were performed to determine the PET content.

[0158] [Table 8]

[0159] Using the procedure according to Example 3, it was found that nearly all of the PET contained in the starting PET / spandex blend was recovered and the resulting PET was completely spandex-free.

[0160] Example 8 (E8a, 8b): Separation of Spandex, PET and Viscose Polymer blends containing spandex / PET / viscose were then processed according to the procedures of Examples 3 and 2. Details and results are shown in Table 6.

[0161] [Table 9]

[0162] Examples 8a and 8b show a stepwise process of separating different polymers from each other. After separating the spandex, the remaining material containing PET and viscose contained 67.3 g of PET. 12 g of this material was treated according to Reference Example 2 to obtain PET8.0 (which is exactly 67.3% of 12 g) with a purity of 99.3%. Thus, PET and viscose could be selectively separated.

[0163] Example 9 (E9): Regeneration of PBT The pigmented PBT material was treated as described in Reference Example 4. The type of polymeric material and the experimental conditions as well as the results are shown in Table 7. Samples before treatment ((pigmented) polymeric material, Table 1) and after the final drying step (regenerated and reobtained discolored solid PBT, Table 7) were analyzed to determine the number average molecular weight Mn, the weight average molecular weight Mw and the polydispersity Mw / Mn.

[0164] [Table 10]

[0165] It was found that by using the PBT dissolving procedure according to Reference Example 4, at least the decrease in the weight average molecular weight Mw was prevented, and the decrease rate was very low, less than 1%. Furthermore, the number average molecular weight Mn was increased. Again, the obtained PBT did not contain glass fibers, and therefore, complete separation could be achieved.

[0166] Comparative Examples 5 and 6 (C5, C6): Other Solvents The colored polymeric material (in any color) was treated as described in Example 1b, except that other solvents were used instead of GVL. The polymeric material was a white woven fabric as described in Table 1. The experimental conditions and results are shown in Table 8.

[0167] [Table 11]

[0168] When DMI or ethyl benzoate were used as solvents under the same conditions as GVL, it was found that the reclaimed PET was of poor quality. When DMI (C5) was used, PET did not precipitate out of the solvent immediately and the yield of reclaimed PET was lower. Furthermore, the rate of PET degradation was significantly increased compared to when GVL was used. In the case of ethyl benzoate (C6), PET did not dissolve at all (94% of the undissolved PET could be re-isolated as filter cake after filtration) and only a small amount of PET was isolated by hot filtration and precipitation. This reclaimed PET was of poor quality.

[0169] Comparative Example 7 (C7): Reproduction of the prior art procedure Methods for dissolving / precipitating PET are disclosed in Wenjun Chen et al. (Wenjun Chen et al.: “Biomass-derived [gamma]-valerolactone: efficient dissolution and accelerated alkaline hydrolysis of polyethylene terephthalate”, Green Chemistry, vol. 23, no. 11, 9 June 2021, pages 4065-4073), in particular the section “PET recycled by dissolution / precipitation method” on page 4071 and the right column of Table 2 on pages 4068 and 4067 for additional information regarding the time required for dissolution.

[0170] First, the number average weight (Mn), mass average weight (Mw), dispersity (Mw / Mn) and its CIE-LAB properties of the white PET woven material sample used were analyzed. The analysis results are shown in Table 9.

[0171] For comparison purposes, we attempted to replicate the experiment of Wenjun Chen et al., swelling at 120°C or for 1 hour, and dissolving at 170°C within 2 minutes. 10 g of white woven PET flakes were charged to the reaction vessel. Note: Wenjun Chen et al. performed their experiments with flakes from PET bottles, but here flakes from PET fabric were used. However, it is known that PET behaves the same regardless of its form of origin (bottle, fabric). 200 g of degassed GVL was added (GVL:PET polymeric material 20:1 by weight) and the mixture was kept at 120°C (1013 mbar) for 1 hour. The temperature was then increased to 170°C and maintained at this temperature for 5 minutes, where it was observed that only a partial dissolution occurred, i.e. solid material remained visible. The mixture was then hot filtered, and water (anti-solvent) was added to the filtered liquid phase at 80°C in a ratio of 20:1 by weight water:polymeric material. As a result of the filtration, the majority of the undissolved PET polymer material, 8.5 g (85% of the initial PET fabric flakes), was collected on the filter, and 1.3 g (13% of the initial PET fabric flakes) of PET was collected as a precipitate from the liquid fraction after adding water. The resulting precipitate was analyzed. The results are shown in Table 9 below.

[0172] For comparison, 10 g of the same white PET fabric flakes were treated at 185° C. for 15 min according to Reference Example 1b with a mass ratio of PET:GVL=1:10, and it was observed that the PET flakes were completely dissolved. Precipitation was achieved by cooling after filtration, i.e. without the addition of anti-solvent. The precipitate obtained was analyzed. The results are shown in Table 9 below.

[0173] [Table 12]

[0174] Firstly, it should be noted that, contrary to what is described by Wenjun Chen et al., the PET textile flakes could not be largely dissolved in 2 minutes, even after 1 hour of so-called "swelling" at 120°C, and even though the 170°C treatment step was extended to 5 minutes, 85% of the initially provided PET textile flakes remained undissolved, whereas the procedure according to Reference Example 1b resulted in complete dissolution of the material and complete recovery as precipitate.

[0175] Secondly, the procedure according to Reference Example 1b not only prevented the decrease in the mass average molecular weight Mw, but also increased the number average molecular weight Mn, whereas the procedure of Wenjun Chen et al. caused a significant decrease in Mn and Mw.

[0176] Third, the CIE-LAB L*a*b* values ​​showed that the recovered PET obtained according to the procedure of Reference Example 1b was significantly whiter (higher L* values) compared to the material obtained using the method described in Wenjun Chen et al. The whiteness of the recovered PET obtained according to the procedure of Reference Example 1b was comparable to the initial "white" PET material, whereas the PET obtained according to the procedure of Wenjun Chen et al. had a noticeable yellow coloration.

[0177] References: - International Publication No. 2016 / 12755A1 Brochure - Wenjun Chen,Yuechao Yang,Xue Lan,Baolong Zhang,Xiaogang Zhang and Tiancheng Mu in Green Chem.,vol.23,no.11,9.June 2021,23,pages 4065-4073, “Dyes and Pigments”Metin Acikyildiz,Kuebra Guenes,Ahmet GuersesSpringer,2016(ISBN:10:3319338900) - Industrial Organic Pigments - Klaus Hunger, Thomas Heber, Martin U. Schmidt, Friedrich Reisinger, Stefan Wanne Wiley-VCH, 4th edition, 2018 (ISBN: 978-3-527-32608-2) - Chemistry and Technology of Natural and Synthetic Dyes and Pigments-Ashis Kumar Samanta,Nasser Awwad,IntechOpen,2020(ISBN:9781789859980,9781789859973,9781839687587) - Encyclopedia of Color,Dyes,Pigments-Volume 1,Gerhard Pfaff,de Gruyter,2021(ISBN:311058588X) - Heinrich Zollinger: Color Chemistry: Synthesis, Properties, and Applications of Organic Dyes and Pigments, 3 rd edition. WILEY-VCH Verlag, Weinheim 2003 (ISBN: 3-906390-23-3) - Klaus Hunger (Ed.): Industrial Dyes: Chemistry, Properties, Applications. WILEY-VCH Verlag, Weinheim 2003 (ISBN: 3-662-01950-7) - Hermann Rath: Textbook of Textile Chemistry, including Textile Chemical Technology. 2nd edition. Springer-Verlag, Berlin, Heidelberg 1963 (ISBN: 978-3-662-00065-6) - Wilfried Kratzert, Rasmus Peichert: Dyes. Quelle & Meyer, Heidelberg 1981 (ISBN: 3-494-01021-8) - Ullmann's Encyclopedia of industrial chemistry, Wiley-VCH, 2000, sections “dyes and pigments” and “dyes, general survey” (ISBN: 9783527303854) - Handbook of Mechanical Solid-Liquid Separation Paperback-April 29, 2004 by Klaus Luckert (Editor) - W.-M.Kulicke and C.Clasen,Viscosimetry of Polymers and Polyelectrolytes,Springer(2003)

Claims

1. (i) a polyester; (ii) one or more components selected from the group consisting of a second polymer, a third polymer, and a filler, the second polymer and the third polymer being different from each other and different from the polyester of (i); 1. A method for separating a polymer blend comprising: (a) providing the polymer blend and providing a solvent comprising gamma-valerolactone; (b) contacting said polymer blend with said solvent comprising gamma-valerolactone at a temperature T1 below 170° C., thereby obtaining a solvent rich in dissolved second polymer and a residue of said polymer blend depleted in said second polymer and comprising said polyester, optionally said third polymer and optionally said filler; and / or (c) contacting said polymer blend provided in (a) or said residue of said polymer blend obtained in (b) with a solvent comprising gamma-valerolactone at a temperature T2 above 170° C., thereby obtaining a solvent enriched in dissolved polyester compared to said solvent provided in (a) and optionally comprising at least a portion of said filler, and optionally a residue of said polymer blend depleted in polyester and optionally comprising said third polymer and optionally said filler or a portion of said filler. The method includes:

2. (b) is (b.1) contacting said polymer blend with said solvent comprising gamma-valerolactone at a temperature T1 below 170° C., thereby obtaining a solvent rich in dissolved second polymer and a residue of said polymer blend depleted in said second polymer and comprising said polyester, optionally said third polymer and optionally said filler; (b.2) separating the solvent obtained in (b.1), enriched in the dissolved second polymer, and the remainder of the polymer blend, preferably by physical separation methods, thereby obtaining a separated solvent enriched in the dissolved second polymer compared to the solvent provided in (a), and the remainder of the polymer blend, depleted in the second polymer and comprising the polyester.

2. A method for separating the polymer blend of claim 1 comprising:

3. (c) is (c.1) contacting the polymer blend provided in (a) or the residue of the polymer blend obtained in (b) or (b.2) with a solvent comprising gamma-valerolactone and having a temperature T1a less than or equal to T2 (T2 being a temperature greater than 170° C.), thereby obtaining a mixture comprising the polymer blend and the solvent; (c.2) heating said mixture obtained in (c.1) with continuous heating to a temperature T2 above 170°C, preferably maintaining T2, said heating from T1a to T2 being preferably carried out at a heating rate in the range of 20K / h to 1000K / h, 25K / h to 900K / h, 30k / h to 800K / h, 40k / h to 700K / h, 60k / h to 600K / h, thereby obtaining a solvent enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a portion of said filler, and optionally a residue of said polymer blend depleted in polyester and comprising said third polymer and optionally said filler or a portion of said filler, (c.3) optionally separating the dissolved polyester-rich solvent obtained in (c.2) from the residue of the polymer blend, preferably by hot filtration, more preferably at a temperature T3 in the range of T2-20°C to T2+20°C (T3=T2±20°C), more preferably at a temperature T3 in the range of T2-10°C to T2+10°C (T3=T2±10°C). and the method preferably comprises: (c.4) contacting the residue of the polymer blend obtained in (c.3), if it contains a residual amount of the polyester, with a solvent comprising gamma-valerolactone, preferably at a temperature T3 as defined above, followed by filtration, thereby obtaining a residue of the polymer blend further depleted in polyester and comprising the third polymer and optionally the filler or a portion of the filler, and a solvent containing the residual amount of the polyester.

3. The method of claim 1 or 2, further comprising:

4. 4. The method of claim 3, wherein if T1a is less than 120°C, the heating is preferably carried out with continuous heating at a heating rate in the range of 20K / h to 1000K / h, 25 / K / h to 900K / h, 30K / h to 800K / h, 40K / h to 700K / h, 60K / h to 600K / h, preferably the heating is carried out such that the mixture obtained in (c.1) is at a temperature in the range of 110-130°C for less than 60 minutes, preferably less than 50 minutes, more preferably less than 40 minutes, more preferably less than 30 minutes, more preferably less than 20 minutes, or if T1a is more than 120°C, the heating is preferably carried out with continuous heating at a heating rate in the range of 0.1-1000K / h, more preferably in the range of 5-500K / h, more preferably in the range of 25-300K / h.

5. (d) cooling the solvent obtained in (c) or (c.3), enriched in dissolved polyester compared to the solvent provided in (a) and optionally comprising at least a portion of said filler, to a temperature below 170°C, preferably below 150°C, more preferably below 140°C, more preferably below 100°C, thereby obtaining precipitated polyester and a solvent reduced in dissolved polyester and optionally comprising at least a portion of said filler, (e) optionally separating the precipitated polyester obtained in (d) from the solvent depleted in dissolved polyester, thereby obtaining precipitated polyester and the solvent depleted in dissolved polyester and optionally containing at least a portion of the filler. and preferably (f) optionally washing the precipitated polyester obtained in (e); (g) optionally drying the precipitated polyester obtained in (e) or the washed precipitated polyester obtained in (f).

5. A method for separating the polymer blend of any one of claims 1 to 4, further comprising:

6. 6. A process for separating polymer blends according to any one of claims 1 to 5, comprising at least partially recycling the separated solvent obtained in (b.2) and / or the separated solvent obtained in (e), optionally after one or more work-up steps, to (b) and / or (c).

7. T1 is a temperature in the range of 110 to less than 170° C., preferably in the range of 110 to 165° C., more preferably in the range of 120 to 150° C.; and / or 7. The process for separating polymer blends according to any one of claims 1 to 6, wherein T2 is a temperature in the range of from above 170°C to 200°C, preferably a temperature in the range of from 175 to 190°C, more preferably a temperature in the range of from 180 to 190°C.

8. 8. Method for separating polymer blends according to any one of claims 1 to 7, wherein said polyester according to (i) is selected from the group consisting of polymers based on 1,4-butanediol and terephthalic acid (polybutylene terephthalate, PBT), polymers based on 1,2-ethanediol and terephthalic acid (polyethylene terephthalate, PET), copolymers of 1,4-butanediol, adipic acid and terephthalic acid (polybutylene adipate terephthalate, PBAT), polymers of 1,2-ethanediol and 2,5-furandicarboxylic acid (polyethylene furanoate, PEF) and mixtures of two or more of said (co)polymers, preferably said polyester according to (i) is a polymer based on 1,4-butanediol and terephthalic acid (PBT) or a polymer based on 1,2-ethanediol and terephthalic acid (PET).

9. 9. The method of separating a polymer blend according to any one of the preceding claims, wherein the second polymer is preferably selected from the group consisting of polyurethane (PU), polyethylene glycol (PEG), polytetrahydrofuran (pTHF), mixtures of said polymers and copolymers of said polymers, and the second polymer is more preferably a copolymer of PU and PEG and / or pTHF, more preferably spandex (copolymer of PU and PEG or PU and pTHF).

10. 10. The method of separating polymer blends according to any one of claims 1 to 9, wherein the third polymer is preferably selected from the group consisting of polyolefins, preferably polyethylene (PE) and polypropylene (PP), polyamide (PA), natural polymers, preferably wool, cotton or viscose, mixtures of two or more of said polymers and copolymers of two or more of said polymers, wherein the third polymer is preferably selected from PA, wool, cotton, viscose and mixtures of two or more of said polymers.

11. The solvent containing gamma-valerolactone is a mixture of gamma-valerolactone, water, and a log K ＯＷ Preferably, the organic solvent is selected from the group consisting of water, C5-C12 alkanes, aliphatic C1-C10 alcohols, C3-C10 ketones, C2-C10 cyclic ketones, HO-[C1-C10 alkyl-O-] ｎ -H (wherein n is an integer ranging from 2 to 1000), C1-C10 alkyl-O-C3-C10 alkyl ether, C3-C10 cyclic ether optionally substituted with one or more C1-C6 alkyl groups, C6-C10 aromatic hydrocarbon optionally substituted with one or more C1-C6 alkyl groups, C2-C10 aliphatic ester, C8-C11 aromatic ester, C5-C10 cyclic carboxylic acid ester (lactone), C3-C12 amide, preferably R １ R ２ N-C(=O)-R ３ (In the formula, R １ , R ２ is independently a C1 to C4 alkyl group, and R ３ is selected from the group consisting of C1-C9 alkyl groups, C1-C10 ester groups, and C1-C6 ether groups), a C3-C6 lactam optionally substituted with one or more substituents selected from C1-C6 alkyl groups, C1-C6 ester groups, and C1-C6 ether groups, and one or more solvents selected from the group consisting of a C5 imidazolidine optionally substituted with one or more C1-C6 alkyl groups, a C5-C7 imidazolidone optionally substituted with one or more C1-C6 alkyl groups.

12. 12. A polyester obtained or obtainable from a process according to any one of claims 1 to 11, preferably from (d), and / or (e), and / or (f), and / or (g) according to claim 5.

13. 13. Use of the precipitated polyester obtained or obtainable from (d), and / or (e), and / or (f), and / or (g) according to claim 5 or according to claim 12 for the production of textile applications, fiber applications, packaging applications, plastic applications, automotive applications, electronic applications, preferably food packaging, beverage packaging, clothing, footwear, wire, cable, preferably when the polyester is selected from PBAT, PEF and PET, preferably PET, the precipitated polyester obtained or obtainable from (d), and / or (e), and / or (f), and / or (g) according to claim 5 or according to claim 12 is used for the production of textile applications, fiber applications, packaging applications, plastic applications, more preferably food packaging, beverage packaging, clothing and footwear, and when the polyester is PBT, the precipitated polyester obtained or obtainable from (d), and / or (e), and / or (f), and / or (g) according to claim 5 or according to claim 12 is used for the production of textile applications, automotive applications or electronic applications, more preferably wire and / or cable.

14. 1. A method of making a product, comprising: (I) providing a polyester according to claim 12; (II) Producing textiles, fibers, packaging, plastics, automotive parts, and electronic components from the polyester provided in (I). The method includes:

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