Process for recovery of a polyalkylene terephthalate based polymer from a colored polymeric material

Abstract

The present invention relates in a first aspect to a process for recovery of a polyalkylene terephthalate based polymer from a colored polymeric material comprising polyalkylene terephthalate based polymer. A second aspect is related to polyalkylene terephthalate based polymer, which is depleted in colorant, obtained or obtainable from the process of the first aspect. A third aspect is related to the use of the polyalkylene terephthalate based polymer, which is depleted in colorant of the second aspect for textile applications, fiber applications, packaging applications or plastic applications, preferably for the production of food packaging, beverage packaging, clothing and foot wear, as well as to a method for preparing a textile from the polyalkylene terephthalate based polymer of the second aspect. A fourth aspect of the invention relates to a process comprising conversion of re-obtained polyalkylene terephthalate based polymer, and a fifth aspect is directed to a process comprising converting the residue.

Description

[0001] Process for recovery of a polyalkylene terephthalate based polymer from a colored polymeric material

[0002] The present invention relates in a first aspect to a process for recovery of a polyalkylene terephthalate based polymer from a colored polymeric material. A second aspect is related to polyalkylene terephthalate based polymer, which is depleted in colorant, obtained or obtainable from the process of the first aspect. A third aspect is related to the use of the polyalkylene terephthalate based polymer, which is depleted in colorant of the second aspect for textile applications, fiber applications, packaging applications or plastic applications, preferably for the production of food packaging, beverage packaging, clothing and foot wear, as well as to a method for preparing a textile from the polyalkylene terephthalate based polymer of the second aspect. A fourth aspect of the invention relates to a process comprising conversion of re-obtained polyalkylene terephthalate based polymer, and a fifth aspect is directed to a process comprising converting a residue.

[0003] The demand for polymeric materials has drastically increased over the last decades. However, the poor biodegradability has led to large amounts of plastic waste, which is in Europe usually incinerated thereby losing valuable materials and generating huge CO2 emissions. Even worse is landfill due to the poor biodegradability. Polymeric materials have been used extensively in the packaging sector, for example, in beverage packaging or food packaging. The vast majority of food and drink today is packaged within plastic bottles and containers, made from, for example, polymeric materials comprising PET. PET is also a main component of clothing nowadays. As these materials typically have poor biodegradability and are also still valuable products, it is desirable for these plastics to be recovered and recycled.

[0004] Although recycling processes have been adopted to convert the waste materials into new production materials, there are still many problems associated with recycling and recovery of polymeric materials. Waste packaging often includes a mixture of different polymeric materials containing also, for example, colorants. The same applies also for textiles, which also comprise a high amount of colored polymeric materials. Therefore, in order to recycle polymeric materials, it is common to separate polymeric materials based on their color and / or their composition. However, this sorting process is labor intensive and / or requires the use of sorting machines.

[0005] Another approach for recovery of polymeric materials includes the dissolving of the polymeric material combined with precipitation. WO 2016 / 12755 A1 discloses an extraction of polyesters from packaging, wherein a first solvent is used for removal of 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 for dissolution and accelerated alkaline hydrolysis of PET. WO 2022 / 221832 A1 describes a process for treatment of a polyethylene terephthalate (PET) stream, wherein a polar solvent is used for dissolution of the PET. The polar solvent is defined based on Hansen parameters, wherein a three dimensional rectangular Hansen room is defined by the parameter for energy from dispersion forces between molecules ( 3D) being in the range of from 15 to 20, the parameter for energy from dipolar intermolecular force between molecules (8P) being in the range of from 4 to 20 and the parameter for energy from hydrogen bonds between molecules (8H) being in the range of from 3 to 10. However, polar solvents were considered as solvents for PET according to said definition, which simply are not suited or are unable to dissolve PET, for example, glycerol triacetate, dimethyl succinate or ethyl levulinate. Thus, even knowing these disclosures, it is still unpredictable therefrom what solvents are precisely suitable to dissolve PET. Furthermore, with an eye on a re-use / re-cycling of the obtained PET, it must be considered detrimental if the PET is degraded during the dissolution / precipitation steps; however, the state of the art discloses lots of solvents, which, even if some kind of dissolution takes place, are not suited to recover non-degraded PET, meaning that even if some kind of polymeric material was re-obtained, it was degraded, for example, in view of reduced polymer chain lengths, reduced molecular weight etc.

[0006] The technical problem underlying the present invention was thus the provision of a process for recovery of a polyalkylene terephthalate based polymer from a colored polymeric material, overcoming these disadvantages, and wherein the process especially enables on one hand a precise selection of solvent(s) suitable to dissolve a polyalkylene terephthalate based polymer, while on the other hand enabling recovery of non-degraded polyalkylene terephthalate based polymer.

[0007] In a first aspect, the invention relates to a process for recovery of a polyalkylene terephthalate based polymer from a colored polymeric material, the process comprising:

[0008] (a) providing the colored polymeric material comprising polyalkylene terephthalate based polymer and providing a first and a second solvent system;

[0009] (b) contacting the colored polymeric material with a first solvent system at a temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the first solvent in the solvent system, which has the lowest boiling point, thereby obtaining a first solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer;

[0010] (c) separating polyalkylene terephthalate based polymer from the first solvent system obtained in (b), thereby re-obtaining polyalkylene terephthalate based polymer; wherein the first solvent system comprises one or more solvent(s), wherein (s1 .1) the solvent system has Hansen solubility parameters with respect to energy from dispersion forces between molecules (5DSS), energy from dipolar intermolecular force between molecules (5PSS) and energy from hydrogen bonds between molecules (5HSS), which fulfill equitation 1

[0011] (8.8)2> 4(6Dss-20)2+ (5PSS-11.8)2+ (5Hss-4.5)2

[0012] [equitation 1];

[0013] (s1.2) each solvent of the solvent system has a boiling point at 1013 hPa of at least 160 °C; and

[0014] (s1.3) solvents having a functional group selected from the group consisting of hydroxyl (OH), amino (NH2), carboxyl (COOH), and thiol (SH) are excluded;

[0015] (i) contacting the re-obtained polyalkylene terephthalate based polymer of (c) with a second solvent system at a temperature T1 , which is < 170 °C, thereby obtaining a second solvent system, which is enriched in colorant compared to the second solvent system provided in

[0016] (a), and a polyalkylene terephthalate based polymer, which is depleted in colorant compared to the colored polymeric material provided in (a); wherein the second solvent system comprises one or more solvents, wherein

[0017] (s2.1) the solvent system has Hansen solubility parameters with respect to

[0018] - energy from dispersion forces between molecules (5DSS),

[0019] - energy from dipolar intermolecular force between molecules (5PSS) and

[0020] - energy from hydrogen bonds between molecules (5HSS), which fulfill equitation 2

[0021] (11)2> 4(6DSS-17.5)2+ (6Pss-7.5)2+ (5Hss-7.5)2

[0022] [equitation 2];

[0023] (s2.2) each solvent of the solvent system has a boiling point at 1013 hPa of at least 150 °C.

[0024] In some embodiments, the process comprises:

[0025] (a) providing the colored polymeric material comprising polyalkylene terephthalate based polymer and providing a first and a second solvent system;

[0026] (b) contacting the colored polymeric material with a first solvent system at a temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the first solvent in the solvent system, which has the lowest boiling point, thereby obtaining a first solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer;

[0027] (c) separating polyalkylene terephthalate based polymer from the first solvent system obtained in (b), thereby re-obtaining polyalkylene terephthalate based polymer; wherein the first solvent system comprises one or more solvent(s), wherein

[0028] (s1.1 ) the solvent system has Hansen solubility parameters with respect to energy from dispersion forces between molecules (5DSS), energy from dipolar intermolecular force between molecules (5PSS) and energy from hydrogen bonds between molecules (5HSS), which fulfill equitation 1

[0029] (8.8)2> 4(6Dss-20)2+ (5PSS-11.8)2+ (5Hss-4.5)2

[0030] [equitation 1];

[0031] (s1.2) each solvent of the solvent system has a boiling point at 1013 hPa of at least 160 °C; and

[0032] (s1.3) solvents having a functional group selected from the group consisting of hydroxyl (OH), amino (NH2), carboxyl (COOH), and thiol (SH) are excluded; wherein the first solvent system comprises one or more solvent(s) selected from the group consisting of gamma valerolactone (GVL), N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone, dimethyl sulfoxide (DMSO), dihydrolevoglucosenon (Gyrene) and mixtures of two or more thereof;

[0033] (i) contacting the re-obtained polyalkylene terephthalate based polymer of (c) with a second solvent system at a temperature T1, which is < 170 °C, thereby obtaining a second solvent system, which is enriched in colorant compared to the second solvent system provided in (a), and a polyalkylene terephthalate based polymer, which is depleted in colorant compared to the colored polymeric material provided in (a); wherein the second solvent system comprises one or more solvents, wherein

[0034] (s2.1) the solvent system has Hansen solubility parameters with respect to

[0035] - energy from dispersion forces between molecules (5DSS),

[0036] - energy from dipolar intermolecular force between molecules (5PSS) and

[0037] - energy from hydrogen bonds between molecules (5HSS), which fulfill equitation 2

[0038] (11)2> 4(6DSS-17.5)2+ (6Pss-7.5)2+ (5Hss-7.5)2

[0039] [equitation 2];

[0040] (s2.2) each solvent of the solvent system has a boiling point at 1013 hPa of at least

[0041] 150 °C; wherein the second solvent system comprises one or more solvents(s) selected from the group consisting of gamma valerolactone (GVL), N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone, dimethyl sulfoxide (DMSO), dihydrolevoglucosenon (Gyrene), cyclohexanone and mixtures of two or more thereof.

[0042] It was surprisingly found that dissolution of a colored polymeric material comprising polyalkylene terephthalate based polymer with a solvent system fulfilling (s1 .1), (s1.2) and preferably also (s1.3), followed by a discoloration with a solvent system fulfilling at least (s2.1) and (s2.2) results in an efficient colorant removal. Furthermore, the process allows to re-obtain a non-de- graded polyalkylene terephthalate based polymer - the Mn of the re-obtained polyalkylene terephthalate based polymer is always about equal to the Mn of the polyalkylene terephthalate based polymer comprised in the polymeric material initially provided. The re-obtained polyalkylene terephthalate based polymer has further a dispersity Mw / Mn (Mass average molecular weight Mw divided by number average molecular weight Mn) in the range of from 70 to 95%, preferably in the range of from 75 to 90 % of the dispersity Mw / Mn of the polyalkylene terephthalate based polymer comprised in the colored polymeric material comprising polyalkylene terephthalate based polymer provided in (a) (100%). Obtaining a non-degraded polyalkylene terephthalate based polymer enables further processing of the polyalkylene terephthalate based polymer in a, preferably closed, loop recycling process. Preferably, the colored polymeric material, which preferably comes from textiles, fibers and / or packaging is thus recycled or recyclable into the same. Naturally, the re-obtained can also be put to any further use without being restricted in this regard.

[0043] It is understood that regarding (b), the expression “contacting the colored polymeric material with a first solvent system at a temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the first solvent in the solvent system, which has the lowest boiling point” means that contacting the colored polymeric material is done with a first solvent system at a temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the first solvent in the solvent system, which has the lowest boiling point of (all) solvents in the solvent system.

[0044] In some embodiments, in the first solvent system used for step (b)

[0045] (s1.3) solvents having a functional group selected from the group consisting of hydroxyl (OH), amino (NH2), carboxyl (COOH), and thiol (SH) are excluded.

[0046] In some embodiments, also for the second solvent system (s2.3) solvents having a functional group selected from the group consisting of hydroxyl (OH), amino (NH2), carboxyl (COOH), and thiol (SH) are excluded.

[0047] In some embodiments, in the first solvent system used for step (b)

[0048] (s1 ,3a) solvents having a functional group selected from the group consisting of hydroxyl (OH), amino (NH2), secondary amine (-NH-), carboxyl (COOH), and thiol (SH) are excluded; and / or, preferably and, in the second solvent system used for step (i) (s2.3a) solvents having a functional group selected from the group consisting of hydroxyl (OH), amino (NH2), secondary amine (-NH-), carboxyl (COOH), and thiol (SH) are excluded.

[0049] In some embodiments, in the first solvent system used for step (b)

[0050] (s1.2) each solvent of the solvent system has a boiling point at 1013 hPa of at least 160 °C; and / or, preferably and,

[0051] In the second solvent system used for step (i)

[0052] (s2.2) each solvent of the solvent system has a boiling point at 1013 hPa of at least 150 °C.

[0053] “Contacting” in step (b) and (i) preferably means that the colored polymeric material or the reobtained polyalkylene terephthalate based polymer respectively is at least partially immersed in the solvent system. Preferably, the colored polymeric material or the re-obtained polyalkylene terephthalate based polymer respectively is at least partially immersed in the (first or second) solvent system in 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 colored polymeric material’s surface or the re-obtained polyalkylene terephthalate based polymer surface respectively are in contact with the solvent system, based on the total respective surface being 100%.

[0054] In step (c) and also in (c.2) described herein below, polyalkylene terephthalate based polymer is re-obtained and additionally a first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer compared to the first solvent system obtained in (b). The re-obtain- ing polyalkylene terephthalate based polymer obtained in (c) may be, due to dissolution and separation, already be to some extend depleted in colorant compared to the colored polymeric material provided in (a) as some of the colorant contained in the colored polymeric material provided in (a) may have also been dissolved and have remained in the first solvent system obtained in (c), (c.2). Further removal of colorant happens then in step (i). Regarding the polyalkylene terephthalate based polymer obtained in (i), “depleted in colorant” means that at least 50 weight-%, preferably at least 60 weight-%, more preferably at least 70 weight-%, more preferably at least 80 weight-%, more preferably at least 90 weight-%, more preferably at least 95 weight-% of the colorant comprised in the colored polymeric material provided in (a), more preferably of the colorant comprised in the polyalkylene terephthalate based polymer contained therein, are removed from the polymeric material. “Enriched in colorant” regarding the second solvent system obtained in (i) means that at least 50 weight-%, preferably at least 60 weight-%, more preferably at least 70 weight-%, more preferably at least 80 weight-%, more preferably at least 90 weight-%, more preferably at least 95 weight-%, of the colorant comprised in the polymeric material provided in (a) more preferably of the colorant comprised in the polyalkylene terephthalate based polymer contained therein, are dissolved in the solvent system.

[0055] Regarding the first solvent system, any solvent system for which 4(bDss-20)2+ (bPss-11 .8)2+ (SHss-4.5)2is larger than (8.8)2(i.e. 77.44) is not suited to dissolve the polyalkylene terephthalate based polymer, and any solvent system for which 4(bDss-20)2+ (5PSs-11.8)2+ (bHss-4.5)2is equal to or smaller than (8.8)2(i.e. 77.44) is suitable for dissolving polyalkylene terephthalate based polymer. Regarding the second solvent system, any solvent system for which 4(bDss- 17.5)2+ (SPss-7.5)2+ (SHss-7.5)2is equal or smaller than (11)2(i.e. 121) is suited to dissolve the colorant while leaving the polyalkylene terephthalate based polymer almost completely undissolved. In case of two or more solvents being part of the first or second solvent system, i.e. n solvents with n being an integer with n>2 and i=1 ... n, the Hansen solubility parameters of the resulting mixture with respect to each of bDss, 6HSSand bPssare calculated, knowing the percentage part of each solvent in the solvent system, as the weighted arithmetic mean from 6DSi, SHsi and 6PSiof each of the n solvents S(i). The Hansen parameters are to be found in BIOVIA COSMOquick 2022.

[0056] Considering the three-dimensional form given by, for example, equitation 1 in the three-dimensional Hansen space, a sphere is formed which has its center at 5DC= 20, 5PC= 11.8 and 5HC= 4.5 and a radius r of 8.8. The doubling of the dispersion parameter value is required, according to Charles Hansen, for achieving a spherical form. A Hansen sphere, since there are no negative values possible for 5H, can also be considered as a dome, i.e. a half-sphere. The same principles apply for the three-dimensional form given by equitation 2 in the three-dimensional Hansen space. PET has Hansen parameters according to the 5thEdition 5.1.03 (2008) of the HANSEN Solubility Parameters in Practice (HSPiP) of 5D = 18.2, <5P = 6.4 and 5H = 6.6 and lies within the spheres but not at a center.

[0057] In some embodiments of the process, contacting in (b) is done at a temperature in the range of from 160 °C to the temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the solvent in the solvent system, which has the lowest boiling point.

[0058] In some embodiments of the process, contacting in (i) is done at a temperature Ti, which is in the range of from 10 to <170 °C wherein Ti is preferably in the range of from 100 to < 170°C, more preferably in the range of from 110 to < 170°C, more preferably in the range of from 110 to 165 °C, more preferably in the range of from 120 to 150 °C. In some embodiments of the process, at least 90 weight-%, preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, of the first solvent system consist of two or more solvent(s), wherein the respective mixture fulfill(s) equitation 1.

[0059] In some embodiments of the process, at least 90 weight-%, preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, of the first solvent system consist of one solvent, which fulfills equitation 1.

[0060] In some embodiments of the process, the one or more solvent(s) of the first solvent system is / are selected from the group consisting of N,N-dimethylbenzamide, N,N-dimethylphenyla- cetamide, 1 ,4-benzoquinone, acetophenone, dimethyl terephthalate, 1 ,3,5-trimethoxybenzene, 2-phenylacetophenone, N-methylcaprolactam, methylbenzoate, methyl-4-methoxybenzoate, butylene carbonate, propylene-glycol-dibenzoate, N-ethylpyrrolidone, benzophenone, di-benzyl malonate, N-ethyl-caprolactam, methyl 2-(5-oxotetrahydrofuran-3-yl)acetate (FAME), propiophenone, N-methoxypropyl-pyrrolidone, 1 ,4-cyclohexanedione, cyclohexane-carbonate, N-methox- yethyl-pyrrolidone, N,N-diethylphenylacetamide, phenyl acetate, 1-(2-hydroxyethyl)pyrrolidin-2- one acetate (HEPAc), N,N-diethylbenzamide, isopropyl-benzoate, cyclohexyl phenyl ketone, phenylacetic acid ethylester, phenylacetat, N-methyl-morpholine, benzyl-propionate, benzylacetate, Neopentyl-glycol-dibenzoate, retrahydrofurfuryl acetate, N-methyl-imidazole, benzyl butyrate, 2-pyrrolidone, 2-phenoxyethanol propionate, 2-phenoxyethyl isobutyrate, N,N-di- propylbenzamide, N,N-dimethylacetamide, N,N-diethylacetamide, dihydrolevoglucosenon (Gyrene), propylenecarbonate, caprolactone, dimethylisosorbide, N-butylpyrrolidone, t-butylpyrroli- done, methyl-1-methyl-5-oxopyrrolidine-3-carboxylate (MMOC), gamma-valerolactone (GVL), delta-valerolactone, gamma butyrolactone, methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate (Rhodiasolv Polarclean), caprolactam, phen ethyl acetate, methyl phenylacetate, benzyl benzoate, N,N-dimethyllactamide (Agnique AMD 3L), and dimethyl sulfoxide (DMSO).

[0061] In some embodiments of the process, the one or more solvent(s) of the first solvent system is / are selected from the group consisting of dihydrolevoglucosenon (Gyrene), propylenecarbonate, caprolactone, dimethylisosorbide, N-butylpyrrolidone, t-butylpyrrolidone, methyl-1-me- thyl-5-oxopyrrolidine-3-carboxylate (MMOC), gamma-valerolactone (GVL), delta-valerolactone, gamma butyrolactone, methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate (RhodiasolvOPolar- clean), caprolactam, phenethyl acetate, methyl phenylacetate, benzyl benzoate, phenyl benzoate, methyl benzoate, propyl benzoate, and dimethyl sulfoxide (DMSO).

[0062] In some embodiments of the process, the one or more solvent(s) of the first solvent system is / are selected from the group consisting of propylenecarbonate, N-butylpyrrolidone, t-butylpyr- rolidone, methyl-1-methyl-5-oxopyrrolidine-3-carboxylate (MMOC), Delta-valerolactone, gamma butyrolactone, methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate (Rhodiasolv®Polarclean), caprolactam, phenethyl acetate, methyl phenylacetate, benzyl benzoate, phenyl benzoate, methyl benzoate, propyl benzoate and GVL.

[0063] In some embodiments of the process, the one or more solvent(s) of the first solvent system is / are selected from the group consisting of propylenecarbonate, N-butylpyrrolidone, t-butylpyr- rolidone, methyl-1-methyl-5-oxopyrrolidine-3-carboxylate (MMOC), Delta-valerolactone, gamma butyrolactone, methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate (Rhodiasolv®Polarclean), caprolactam, phenethyl acetate, methyl phenylacetate, benzyl benzoate, phenyl benzoate, methyl benzoate, and propyl benzoate.

[0064] In some embodiments of the process, the one or more solvent(s) of the first solvent system is / are selected from the group consisting of propylenecarbonate, N-butylpyrrolidone, t-butylpyr- rolidone, methyl-1-methyl-5-oxopyrrolidine-3-carboxylate (MMOC), methyl 5-(dimethylamino)-2- methyl-5-oxopentanoate (Rhodiasolv®Polarclean), phenethyl acetate, and GVL.

[0065] In some embodiments of the process, the one or more solvent(s) of the first solvent system is / are selected from the group consisting of propylenecarbonate, N-butylpyrrolidone, t-butylpyr- rolidone, methyl-1-methyl-5-oxopyrrolidine-3-carboxylate (MMOC), methyl 5-(dimethylamino)-2- methyl-5-oxopentanoate (Rhodiasolv®Polarclean), and phenethyl acetate.

[0066] In some embodiments of the process, the one or more solvent(s) of the first solvent system is / are selected from the group consisting of gamma valerolactone (GVL), N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone, dimethyl sulfoxide (DMSO), dihydrolevoglucosenon (Cyrene) and mixtures of two or more thereof. In some embodiments of the process, the one or more solvent(s) of the first solvent system is / are selected from the group consisting of gamma valerolactone (GVL), N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone, dimethyl sulfoxide (DMSO) and mixtures of two or more thereof. In some embodiments of the process, the one or more solvent(s) of the first solvent system is / are selected from the group consisting of gamma valerolactone (GVL), N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone and mixtures of two or more thereof. In some embodiments of the process, the one or more solvents) of the first solvent system is / are selected from the group consisting of gamma valerolactone (GVL), N-butylpyrrolidone (NBP), acetophenone and mixtures of two or more thereof. In some embodiments of the process, the one or more solvent(s) of the first solvent system is / are selected from the group consisting of gamma valerolactone (GVL), N-butylpyrrolidone (NBP) and mixtures of GVL and NBP. In some embodiments of the process, the one or more solvent(s) of the first solvent system is / are selected from the group consisting of N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone, dimethyl sulfoxide (DMSO), dihydrolevoglucosenon (Cyrene) and mixtures of two or more thereof. In some embodiments of the process, the one or more solvent(s) of the first solvent system is / are selected from the group consisting of N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone, dimethyl sulfoxide (DMSO) and mixtures of two or more thereof. In some embodiments of the process, the one or more solvent(s) of the first solvent system is / are selected from the group consisting of N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone and mixtures of two or more thereof. In some embodiments of the process, the one or more solvent(s) of the first solvent system is / are selected from the group consisting of N-bu- tylpyrrolidone (NBP), acetophenone and mixtures of N-butylpyrrolidone (NBP) and acetophenone.

[0067] In some embodiments of the process, the one or more solvent(s) of the first solvent system comprise at least N-butylpyrrolidone, preferably at least 90 weight-% of the one or more solvents), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are N-butylpyrrolidone, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is N-butylpyr- rolidone. In some embodiments, contacting in (b) is done at a temperature T, which may be in the range of from 160 °C to the temperature T, which is at least 7K below the boiling temperature of the N-butylpyrrolidone, preferably at a temperature T in the range of from 180 to 200 °C, more preferably in the range of from 185 to 195 °C or contacting in (b) is done at a temperature T, which may be in the range of from 61 to 41 K below the boiling point of the of the N-butylpyr- rolidone, preferably in the range of from 56 to 46 K below the boiling point of the of the N-bu- tylpyrrolidone. The contacting in (b) is preferably done at a pressure in the range of from 800 to 1200 hPa. Preferably, the process is run at autogenous pressure, wherein the autogenous pressure may be higher than the ambient pressure of the surrounding area caused by the steam pressure of N-butylpyrrolidone at the temperature T at which the process is run. The skilled person can determine and / or adjust said autogenous pressure according to the steam pressure curve of N-butylpyrrolidone at a certain temperature T. Steam pressure curves of N- butylpyrrolidone are known to a person skilled in the art. The autogenous pressure may be lowered by purging, e.g. by a purging valve, preferably to a pressure between ambient pressure and lower 2000 hPa, preferably between 1200 hPa and 1800 hPa. Autogenous pressure is the pressure caused by the production system itself in a closed system, e.g. a pressure in the range from 800 to 3000 hPa. In some embodiments of the process, the one or more solvent(s) of the first solvent system comprise at least propylenecarbonate, preferably at least 90 weight-% of the one or more solvents), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are propylenecarbonate, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is propylenecarbonate. In some embodiments, contacting in (b) is done at a temperature T, which may be in the range of from 160 °C to the temperature T, which is at least 7K below the boiling temperature of the propylenecarbonate, preferably at a temperature T in the range of from 185 to 205 °C, more preferably in the range of from 190 to 200 °C or contacting in (b) is done at a temperature T, which may be in the range of from 57 to 37 K below the boiling point of the of the propylenecarbonate, preferably in the range of from 52 to 42 K below the boiling point of the of the propylenecarbonate. The contacting in (b) is preferably done at a pressure in the range of from 800 to 1200 hPa. Preferably, the process is run at autogenous pressure, wherein the autogenous pressure may be higher than the ambient pressure of the surrounding area caused by the steam pressure of propylenecarbonate at the temperature T at which the process is run. The skilled person can determine and / or adjust said autogenous pressure according to the steam pressure curve of propylenecarbonate at a certain temperature T. Steam pressure curves of propylenecarbonate are known to a person skilled in the art. The autogenous pressure may be lowered by purging, e.g. by a purging valve, preferably to a pressure between ambient pressure and lower 2000 hPa, preferably between 1200 hPa and 1800 hPa. Autogenous pressure is the pressure caused by the production system itself in a closed system, e.g. a pressure in the range from 800 to 3000 hPa.

[0068] In some embodiments of the process, the one or more solvent(s) of the first solvent system comprise at least acetophenone, preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are acetophenone, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is acetophenone. In some embodiments, contacting in (b) is done at a temperature T, which may be in the range of from 160 °C to the temperature T, which is at least 7K below the boiling temperature of the acetophenone, preferably at a temperature T in the range of from 165 to 185 °C, more preferably in the range of from 170 to 180 °C or contacting in (b) is done at a temperature T, which may be in the range of from 37 to 17 K below the boiling point of the of the acetophenone, preferably in the range of from 32 to 22 K below the boiling point of the of the acetophenone. The contacting in (b) is preferably done at a pressure in the range of from 800 to 1200 hPa. Preferably, the process is run at autogenous pressure, wherein the autogenous pressure may be higher than the ambient pressure of the surrounding area caused by the steam pressure of acetophenone at the temperature T at which the process is run. The skilled person can determine and / or adjust said autogenous pressure according to the steam pressure curve of acetophenone at a certain temperature T. Steam pressure curves of acetophenone are known to a person skilled in the art. The autogenous pressure may be lowered by purging, e.g. by a purging valve, preferably to a pressure between ambient pressure and lower 2000 hPa, preferably between 1200 hPa and 1800 hPa. Autogenous pressure is the pressure caused by the production system itself in a closed system, e.g. a pressure in the range from 800 to 3000 hPa.

[0069] In some embodiments of the process, the one or more solvent(s) of the first solvent system comprise at least dimethyl sulfoxide (DMSO), preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are DMSO, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is DMSO. In some embodiments, contacting in (b) is done at a temperature T, which may be in the range of from 160 °C to the temperature T, which is at least 1K below the boiling temperature of the DMSO, preferably at a temperature T in the range of from 170 to 188 °C, more preferably in the range of from 175 to 188 °C or contacting in (b) is done at a temperature T, which may be in the range of from 19 to 1 K below the boiling point of the of the DMSO, preferably in the range of from 14 to 1 K below the boiling point of the of the DMSO. The contacting i (b) is preferably done at a pressure in the range of from 800 to 1200 hPa. Preferably, the process is run at autogenous pressure, wherein the autogenous pressure may be higher than the ambient pressure of the surrounding area caused by the steam pressure of DMSO at the temperature T at which the process is run. The skilled person can determine and / or adjust said autogenous pressure according to the steam pressure curve of DMSO at a certain temperature T. Steam pressure curves of DMSO are known to a person skilled in the art. The autogenous pressure may be lowered by purging, e.g. by a purging valve, preferably to a pressure between ambient pressure and lower 2000 hPa, preferably between 1200 hPa and 1800 hPa. Autogenous pressure is the pressure caused by the production system itself in a closed system, e.g. a pressure in the range from 800 to 3000 hPa.

[0070] In some embodiments of the process, the one or more solvent(s) of the first solvent system comprise at least dihydrolevoglucosenon (Gyrene), preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are Gyrene, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is Gyrene. In some embodiments, contacting in (b) is done at a temperature T, which may be in the range of from 160 °C to the temperature T, which is at least 7K below the boiling temperature of the Cyrene, preferably at a temperature T in the range of from 160 to 180 °C, more preferably in the range of from 160 to 170 °C or contacting in (b) is done at a temperature T, which may be in the range of from 66 to 46 K below the boiling point of the of the Cyrene, preferably in the range of from 66 to 56 K below the boiling point of the of the Cyrene. The contacting in (b) is preferably done at a pressure in the range of from 800 to 1200 hPa. Preferably, the process is run at autogenous pressure, wherein the autogenous pressure may be higher than the ambient pressure of the surrounding area caused by the steam pressure of Cyrene at the temperature T at which the process is run. The skilled person can determine and / or adjust said autogenous pressure according to the steam pressure curve of Cyrene at a certain temperature T. Steam pressure curves of Cyrene are known to a person skilled in the art. The autogenous pressure may be lowered by purging, e.g. by a purging valve, preferably to a pressure between ambient pressure and lower 2000 hPa, preferably between 1200 hPa and 1800 hPa. Autogenous pressure is the pressure caused by the production system itself in a closed system, e.g. a pressure in the range from 800 to 3000 hPa.

[0071] In some embodiments of the process, ethyl benzoate and butyl benzoate are excluded as solvents) of the first solvent system.

[0072] GVL

[0073] In some embodiments of the process, the first solvent system comprises GVL, wherein preferably at least 90 weight-%, more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably in the range of from 99 to 100 weight-%, based on the total weight of the first solvent system being 100 weight-%, of the first solvent system consist of GVL, more preferably the one solvent is GVL. In some embodiments, contacting in (b) is done at a temperature T, which is in the range of from 160 °C to the temperature T, which may be at least 7K below the boiling temperature of the GVL, preferably at a temperature T in the range of from 175 to 195 °C, more preferably in the range of from 180 to 190 °C or contacting in (b) is done at a temperature T, which may be in the range of from 30 to 10 K below the boiling point of the of the GVL, preferably in the range of from 25 to 15 K below the boiling point of the of the GVL. The contacting in (b) is preferably done at a pressure in the range of from 800 to 1200 hPa. Preferably, the process is run at autogenous pressure, wherein the autogenous pressure may be higher than the ambient pressure of the surrounding area caused by the steam pressure of GVL at the temperature T at which the process is run. The skilled person can determine and / or adjust said autogenous pressure according to the steam pressure curve of GVL at a certain temperature T. Steam pressure curves of GVL are known to a person skilled in the art. The autogenous pressure may be lowered by purging, e.g. by a purging valve, preferably to a pressure between ambient pressure and lower 2000 hPa, preferably between 1200 hPa and 1800 hPa. Autogenous pressure is the pressure caused by the production system itself in a closed system, e.g. a pressure in the range from 800 to 3000 hPa.

[0074] In some embodiments of the process, the re-obtained polyalkylene terephthalate based polymer of (c) has a number average molecular weight Mn, which is greater or at least equal to the Mn of the polyalkylene terephthalate based polymer comprised in the polymeric material provided in (a).

[0075] In some embodiments of the process, the re-obtained polyalkylene terephthalate based polymer of (c) has a dispersity Mw / Mn (Mass average molecular weight Mw divided by number average molecular weight Mn) in the range of from 70 to 95%, preferably in the range of from 75 to 90 % of the dispersity Mw / Mn of the polyalkylene terephthalate based polymer comprised in the polymeric material provided in (a) (100%).

[0076] Polyalkylene terephthalate based polymer

[0077] In some embodiments of the process, at least 50 weight-%, preferably at least 60 weight-%, more preferably at least 70 weight-%, more preferably at least 80 weight-%, more preferably at least 90 weight-%, more preferably at least 95 weight-%, more preferably at least 98 weight-% of the polymeric material comprising polyalkylene terephthalate based polymer are polyalkylene terephthalate based polymer, based on the total weight of the polymeric material comprising polyalkylene terephthalate based polymer being 100 weight-%.

[0078] The “polyalkylene terephthalate based polymer” consists of either oxyethylen units or oxy- butylen units and oxyterephthaloyl units, wherein in case of oxyethylen units, in the range of from 0 to 5 mol-% of the oxyterephthaloyl units are replaced by oxyisophthaloyl units and / or in the range of from 0 to 49 mol-% of the oxyethylen units are replaced by oxymethylene cyclohexylene methylene units. Preferably, the polyalkylene terephthalate based polymer is selected from the group consisting of PET (polyethylene terephthalate), PETG (poly(ethylene tereph- thalate-co-1,4-cyclohexylene dimethylene terephthalate)), PETI (poly(ethylene terephthalate-co- isophthalate)), PBT (polybutylene terephthalate), and mixtures of two or three of these polymers, or the polyalkylene terephthalate based polymer is selected from the group consisting of PET (polyethylene terephthalate), PETI (poly(ethylene terephthalate-co-isophthalate)), PBT (polybutylene terephthalate), and mixtures of two or three of these polymers. In some embodiments, the polyalkylene terephthalate based polymer comprises at least 80 weight-%, more preferably at least 85 weight-%, more preferably at least 90 weight-%, more preferably at least 95 weight-%, more preferably at least 96 weight-%, more preferably at least 97 weight-%, of PET based on the total weight of the polyalkylene terephthalate based polymer being 100 weight-% and / or, preferably and, at the outmost 20 weight-%, more preferably at the outmost 15 weight-%, more preferably at the outmost 10 weight-%, more preferably at the outmost 5 weight-%, more preferably at the outmost 4 weight-%, more preferably at the outmost 3 weight- %, more preferably at the outmost 2 weight-%, more preferably at the outmost 1 weight-%, of PETI, based on the total weight of the polyalkylene terephthalate based polymer being 100 weight-%.

[0079] In some embodiments, the “polyalkylene terephthalate based polymer” comprises or is a polyester based on 1 ,4-butanediol or 1 ,2-ethandiol, more preferably a polyester selected from the group consisting of a polymer based on 1 ,4-butanediol and terephthalic acid (polybutylene terephthalate, PBT), a polymer based on 1 ,2-ethanediol and terephthalic acid (polyethylene terephthalate, PET), a copolymer of 1 ,4-butanediol, adipic acid and terephthalic acid (polybutyl- enadipat-terephthalat, PBAT), a polymer of 1 ,2-ethanediol and 2,5-furandicarboxylic acid (polyethylene furanoate, PEF) and mixtures of two or more of these (co)polymers.

[0080] More preferably, the “polyalkylene terephthalate based polymer” comprises at least PET and / or PBT, more preferably the polyester is PET or PBT or a mixture of PET and PBT.

[0081] More preferably the polyalkylene terephthalate based polymer comprises or is PET.

[0082] In some embodiments of the process, the polymeric material comprising polyalkylene terephthalate based polymer further comprises at least one polymer different from polyalkylene terephthalate based polymer and optionally at least one colorant. In some embodiments with at least one polymer different from polyalkylene terephthalate based polymer, the polymeric material comprising polyalkylene terephthalate based polymer is considered a polymer blend, wherein said at least one polymer different from polyalkylene terephthalate based polymer is in some embodiments selected from polypropylene (PP), polyethylene (PE), polyamide (PA), natural polymer such as cotton, viscose and linen. “At least one” means one but also two or more. A “polymer blend” means a combination of at least one polymer with at least one further component, which is at least another polymer, these components combined with each other in any suitable way. For example, in case of at least two polymers, the polymers are intermixed, or one or more polymer(s) are embedded in and / or interwoven with one or more other polymer(s), or the polymers are aligned in separate layers, as well as hybrid forms of these combinations. PP, PE, PA, natural polymer, viscose and linen such as cotton, viscose and / or linen are mostly not dissolved together with the polyalkylene terephthalate based polymer but rather remain undissolved. PA comprises preferably PA6 and PA66; however, in some embodiments, the content of PA6 as further polymer is reduced and preferably, the polymeric material comprising polyalkylene terephthalate based polymer provided in (a) comprises only less than 10 weight-% PA6. In some embodiments, the polymeric material derives from textiles such as clothing, wherein the textiles are preferably subjected to a sorting process before the polymeric material is subjected to a method according to the present invention. A sorting process preferably comprises one or more NIR sorting steps, wherein textiles are analysed by near-infrared (NIR) spectroscopy and, based on the analytic result, sorted based on their composition. Thus, the polymeric material subjected to the method according to the present invention is preferably a presorted, more preferably an NIR presorted, textile. The textile has preferably underwent a size reduction, more preferably a cutting and / or shredding step. Thus, the polymeric material subjected to the method according to the present invention is preferably a pre-sorted, more preferably an NIR presorted, and / or size reduced, more preferably shredded, textile. In some embodiments, the polymeric material subjected to the method according to the present invention is preferably a pre-sorted, more preferably an NIR presorted, and / or size reduced, more preferably shredded, textile, which has a content of PA6 of less than 10 weight-%, more preferably of less than 5 weight-%, more preferably of less than 4 weight-%, more preferably of less than 3 weight-%, more preferably of less than 2 weight-%, more preferably of less than 1 weight-%, based on the total weight of the polymeric material being 100 weight-%. Lowering the content of PA in the textile may provide an improved quality of the obtained polyester, in particular of the polyalkylene terephthalate based polymer. If present in the polymeric material comprising polyalkylene terephthalate based polymer, the solvent system obtained in (c), which is enriched in dissolved polyalkylene terephthalate based polymer is separated from the residue, which comprises at least one of PP, PE, PA and / or natural polymer. All polymers not soluble together with the polyalkylene terephthalate based polymer, preferably all polymers not soluble together with the polyalkylene terephthalate based polymer in a solvent system as defined above under the conditions of step (b) as defined above, are called herein “insoluble polymers”.

[0083] In some embodiments of the process, (b), if at least one insoluble polymer is present in the colored polymeric material comprising polyalkylene terephthalate based polymer provided in (a), preferably comprises:

[0084] (b.1 ) contacting the colored polymeric material with a first solvent system at a temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the first solvent in the solvent system, which has the lowest boiling point, thereby obtaining a first solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer; and a residue comprising at least one insoluble polymer selected from PP, PE, PA, natural polymer, viscose and linen;

[0085] (b.2) optionally separation of the solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer from the residue, thereby obtaining an insoluble polymer-free solvent system enriched in dissolved polyalkylene terephthalate based polymer and a residue comprising at least one insoluble polymer selected from PP, PE, PA, natural polymer, viscose and linen, wherein the separation is preferably done by heated filtration.

[0086] The heated filtration is preferably done at a temperature in the range of T ± 20°C, more preferably at a temperature in the range of T ± 10°C. In heated filtration, the solution, filter, and funnel are heated, preferably heated so that each has temperature T ± 20°C or T ± 10°C. In some embodiments, it is preferred that the heated filtration is done under a pressure of >1bar, more preferably at a pressure in the range of from 1 bar to 30 bar, preferably in the range of from 1 to 10 bar, more preferably in the range of from 1 to 6 bar (heated pressure filtration). Other means and methods for the separation are known to the skilled person such as non-heated filtration or heated centrifugation. In some embodiments, the filter and the residue comprising at least one insoluble polymer (which is retained on the filter), preferably after the solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer and optionally in additive, has passed through the filter, is rinsed with a solvent system for one or more times, preferably with a first solvent system having the same composition as provided in (a) and used in (b), wherein the solvent system preferably has temperature T ± 20°C or T ± 10°C. In some embodiments, it is preferred that the solvent system, to which the cooling in (c.1) is applied, comprises the solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer and optionally in additive obtained in (b.1), which had been subjected to filtration and the rising charge(s).

[0087] In some embodiments of the process, (b), preferably (b.1) and / or (i) is / are done in counter current mode. For example, if the contacting of step (b) or (b.1) and / or (c) is done within a vessel, the solvent system enters the vessel from one direction (either side or top / bottom) and the colored polymeric material enters the vessel from an another, preferably an opposite, direction. In a preferred constellation wherein a vertically arranged vessel is used, the solvent system enters the vessel from the bottom and the colored polymeric material enters the vessel from the top. In some embodiments of the process, (b) or (b.1) and / or (c) is / are conducted under mechanical intermixing, wherein mechanical intermixing preferably comprises one or more methods selected from stirring, blending, and ultra sound.

[0088] In some embodiments of the process, at least 40 weight-%, more preferably at least 50 weight- %, more preferably at least 60 weight-%, more preferably at least 70 weight-%, more preferably at least 80 weight-%, more preferably at least 90 weight-% of the polymeric material comprising polyalkylene terephthalate based polymer are the polyalkylene terephthalate based polymer, and at the outmost 60 weight-%, more preferably at the outmost 50 weight-%, more preferably at the outmost 40 weight-%, more preferably at the outmost 30 weight-%, more preferably at the outmost 20 weight-%, more preferably at the outmost 10 weight-% of the polymeric material comprising polyalkylene terephthalate based polymer are at least one polymer different from polyalkylene terephthalate based polymer and optionally at least one colorant, each based on the total weight of the polymeric material comprising polyalkylene terephthalate based polymer being 100 weight-%.

[0089] In some embodiments of the process, polymeric material comprising polyalkylene terephthalate based polymer and first solvent system are contacted in a mass-based ratio solvent system: polymeric material in the range of from 1 :1 to 100:1 , preferably in the range of from 1 :1 to 50:1 , more preferably in the range of from 1 :1 to 20:1 , more preferably in the range of from 1 :1 to 10:1.

[0090] In some embodiments of the process, (b) and (c), preferably (a), (b) and (c) are done at a pressure in the range of from 800 to 200,000 hPa. The same applies for all substeps of (b) and (c) described above and in the following. In some embodiments of the process, (b) and (c), preferably (a), (b) and (c) are done at pressure in the range of from 800 to 1200 hPa. The same applies for all substeps of (b) and (c) described above and in the following.

[0091] In some embodiments, (b), if at least one insoluble polymer is present, comprises

[0092] (b.3) optionally washing the residue comprising at least one insoluble polymer selected from

[0093] PP, PE, PA, natural polymer, viscose and linen, thereby obtaining a washed residue; and optionally

[0094] (b.4) optionally drying the washed residue obtained in (b.3).

[0095] Washing in optional step (b.3) is preferably done with a solvent system having features (s.1), (s.2) and (s.3) as defined above, preferably with a solvent system comprising one or more of the solvent(s) of any one of the groups defined above. In some embodiments, washing is done with a solvent selected from the group consisting of methanol, ethanol, propanol, isopropanol, acetonitrile, ethyl acetate, acetone, water or a mixture of two or more of these solvents. In some embodiments, the washing in step (b.3) is done with a solvent selected from the group consisting of methanol, ethanol, propanol, isopropanol, acetonitrile, ethyl acetate, acetone, water, GVL, or a mixture of two or more of these solvents. Drying in optional step (b.4) is preferably done under one or more conditions selected from the group consisting of a pressure in the range of from 1 to 1013 mbar; a temperature in the range of from 50 to 210 °C, preferably in the range of from 60 to 180°C, more preferably in the range of from 80 to 160 °C; drying time in the range of from 30 minutes to 24 hours; drying in an atmosphere comprising nitrogen, preferably in an atmosphere having at least 90 volume-%, more preferably 95 volume-%, more preferably at least 98 volume-% nitrogen. Drying is done by one or more methods selected from the group consisting of contact drying, convection drying and radiation drying.

[0096] Optionally, the process comprises between (b) and (c) a heated filtration of the first solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer, obtained in (b), more preferably a heated filtration at a temperature in the range of T ± 20°C, more preferably at a temperature in the range of T ± 10°C. In heated filtration, the solution, filter, and funnel are heated, preferably heated so that each has temperature T ± 20°C or T ± 10°C. In some embodiments, it is preferred that the heated filtration is done at a pressure of >1 bar, more preferably at a pressure in the range of from 1 bar to 30 bar, preferably in the range of from 1 to 10 bar, more preferably in the range of from 1 to 6 bar (heated pressure filtration). Other means and methods for the separation are known to the skilled person such as non-heated filtration or centrifugation. In some embodiments, the filter, preferably after the solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer and optionally in additive, has passed through it, is rinsed with first solvent system for one or more times, preferably with first solvent system having the same composition as provided in (a) and used in (b), wherein the first solvent system preferably has temperature T ± 20°C or T ± 10°C. In some embodiments, it is preferred that the solvent system, to which the cooling in (c.1) is applied, comprises the solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer and optionally in additive obtained in (b), which had been subjected to filtration and the rising charge(s).

[0097] In some embodiments of the process, (c) comprises:

[0098] (c.1) optionally after heated filtration, cooling the first solvent system obtained in (b) which is enriched in dissolved polyalkylene terephthalate based polymer compared to the first solvent system provided in (a) to a temperature below 160°C, preferably below 150°C, more preferably below 140°C, more preferably below 120°C;

[0099] (c.2) obtaining a precipitated polyalkylene terephthalate based polymer and a first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer.

[0100] In some embodiments of the process, cooling in (c.1) is done without addition of anti-solvents.

[0101] In some embodiments the process comprises

[0102] (d) separating the precipitated polyalkylene terephthalate based polymer obtained in (c) or (c.2) from the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer, thereby obtaining a precipitated polyalkylene terephthalate based polymer and the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer. The separation in (d) is done by methods and means known to the skilled person, especially solid-liquid separation methods such as filtration, for example, heated pressure filtration, sedimentation or centrifugation (see Handbuch der mechanischen Fest-Flussig-Trennung Taschen- buch - 29. April 2004 von Klaus Luckert (Herausgeber)). Colorants remain at least partially in the separated solvent system obtained in (d).

[0103] In some embodiments the process comprises

[0104] (e) optionally washing the precipitated polyalkylene terephthalate based polymer obtained in (d);

[0105] (f) drying the precipitated polyalkylene terephthalate based polymer obtained in (d) or the washed precipitated polyalkylene terephthalate based polymer obtained in (e).

[0106] Washing in optional step (e) is preferably done with a solvent system having features (s.1 ), (s.2) and (s.3) as described above, preferably with a solvent system comprising one or more of the solvent(s) of any one of the groups listed above. In some embodiments, washing is done with a solvent selected from the group consisting of methanol, ethanol, propanol, isopropanol, acetonitrile, ethyl acetate, acetone, water or a mixture of two or more of these solvents. In some embodiments, the washing in optional step (e) is done with a solvent selected from the group consisting of methanol, ethanol, propanol, isopropanol, acetonitrile, ethyl acetate, acetone, water, GVL, or a mixture of two or more of these solvents. Drying in step (f) is preferably done under one or more conditions selected from the group consisting of a pressure in the range of from 1 to 1013 mbar; a temperature in the range of from 50 to 210 °C, preferably in the range of from 60 to 180°C, more preferably in the range of from 80 to 160 °C; drying time in the range of from 30 minutes to 24 hours; drying in an atmosphere comprising nitrogen, preferably in an atmosphere having at least 90 volume-%, more preferably 95 volume-%, more preferably at least 98 volume-% nitrogen. Drying is done by one or more methods selected from the group consisting of contact drying, convection drying and radiation drying.

[0107] In some embodiments of the process, separation step (d) and washing step (e) are directly replaced by step (i). Thus, instead of separation of the precipitated polyalkylene terephthalate based polymer obtained in (c) or (c.2) from the first solvent system in (d) and washing with a washing solvent in (e), the precipitated polyalkylene terephthalate based polymer obtained in (c) or (c.2) is separated from the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer, thereby obtaining a precipitated polyalkylene terephthalate based polymer and the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer, followed by contacting the re-obtained polyalkylene terephthalate based polymer with the second solvent system at a temperature Ti, which is < 170 °C, thereby obtaining a second solvent system, which is enriched in colorant compared to the second solvent system provided in (a), and a polyalkylene terephthalate based polymer, which is depleted in colorant compared to the colored polymeric material provided in (a).

[0108] According to these embodiments, the process preferably comprises:

[0109] (a) providing the colored polymeric material comprising polyalkylene terephthalate based polymer and providing a first and a second solvent system;

[0110] (b) contacting the colored polymeric material with a first solvent system at a temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the first solvent in the solvent system, which has the lowest boiling point, thereby obtaining a first solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer;

[0111] (c) separating polyalkylene terephthalate based polymer from the first solvent system obtained in (b), thereby re-obtaining polyalkylene terephthalate based polymer comprising (c.1) optionally after heated filtration, cooling the first solvent system obtained in (b) which is enriched in dissolved polyalkylene terephthalate based polymer compared to the first solvent system provided in (a) to a temperature below 160°C, preferably below 150°C, more preferably below 140°C, more preferably below 120°C;

[0112] (c.2) obtaining a precipitated polyalkylene terephthalate based polymer and a first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer;

[0113] (i’.1) separating the precipitated polyalkylene terephthalate based polymer obtained in (c.2) from the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer, thereby obtaining a precipitated polyalkylene terephthalate based polymer and the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer;

[0114] (i’.2) contacting the precipitated polyalkylene terephthalate based polymer of (i’.1) with a second solvent system at a temperature Ti, which is < 170 °C, thereby obtaining a second solvent system, which is enriched in colorant compared to the second solvent system provided in (a), and a polyalkylene terephthalate based polymer, which is depleted in colorant compared to the colored polymeric material provided in (a).

[0115] Preferably, steps (i’.1) and (i’.2) are carried out within the same device, such as a filtration device suitable for heated filtration at an adjustable temperature. A process with steps (i’.1) and (i’.2) offers the advantage that less process steps and less equipment are required compared to a process, wherein steps (d), (e) and step (i) are carried out separately or compared to a process wherein a colored polymeric material has to be initially discolored, before dissolution. A schematic overview comparing both process variants is shown in Fig. 1. Preferably, step (i’.2) follows directly after step (i’.1), i.e. no intermediate step is carried out between step (i’.1) and step (i’.2) and, as indicated above, both steps (i’.1) and (i’.2) are carried out within the same device.

[0116] In some embodiments of the process, the second solvent system comprises one or more solvents), wherein

[0117] (s2.1a) the solvent system has Hansen solubility parameters with respect to

[0118] - energy from dispersion forces between molecules (bDss),

[0119] - energy from dipolar intermolecular force between molecules (bPss) and

[0120] - energy from hydrogen bonds between molecules (5HSs), which fulfill equitation 1

[0121] (8.8)2> 4(5Dss-20)2+ (SPss-11.8)2+ (5Hss-4.5)2

[0122] [equitation 1];

[0123] (s2.2a) each solvent of the solvent system has a boiling point at 1013 hPa of at least

[0124] 150 °C; and,

[0125] (s2.3a) solvents having a functional group selected from the group consisting of hydroxyl (OH), amino (NH2), carboxyl (COOH), and thiol (SH) are excluded.

[0126] In some embodiments,

[0127] (s1 ,3b) solvents having a functional group selected from the group consisting of hydroxyl (OH), amino (NH2), secondary amine (-NH-), carboxyl (COOH), and thiol (SH) are excluded for the first solvent system; and / or, preferably and;

[0128] (s2.3b) solvents having a functional group selected from the group consisting of hydroxyl (OH), amino (NH2), secondary amine (-NH-), carboxyl (COOH), and thiol (SH) are excluded for the second solvent system.

[0129] In some embodiments of the process, the one or more solvent(s) of the second solvent system is / are selected from one of the preferred groups indicated above for the first solvent system, wherein preferably also ethyl benzoate and butyl benzoate are excluded as solvent(s) of the second solvent system.

[0130] In some embodiments of the process, at least 90 weight-%, preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, of the second solvent system consist of two or more solvent(s), wherein the respective mixture fulfill(s) equitation 2 or equitation 1.

[0131] In some embodiments of the process, at least 90 weight-%, preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, of the first solvent system consist of one solvent, which fulfills equitation 2 or equitation 1. In some embodiments of the process, ethyl benzoate and butyl benzoate are excluded as solvents) of the second solvent system.

[0132] In some embodiments of the process, the one or more solvent(s) of the second solvent system is / are selected from the group consisting of gamma valerolactone (GVL), N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone, dimethyl sulfoxide (DMSO), dihydrolevoglucosenon (Gyrene), cyclohexanone and mixtures of two or more thereof. In some embodiments of the process, the one or more solvent(s) of the second solvent system is / are selected from the group consisting of gamma valerolactone (GVL), N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone, dimethyl sulfoxide (DMSO), dihydrolevoglucosenon (Gyrene) and mixtures of two or more thereof. In some embodiments of the process, the one or more solvent(s) of the second solvent system is / are selected from the group consisting of gamma valerolactone (GVL), N-bu- tylpyrrolidone (NBP), propylenecarbonate, acetophenone, dimethyl sulfoxide (DMSO) and mixtures of two or more thereof. In some embodiments of the process, the one or more solvent(s) of the second solvent system is / are selected from the group consisting of gamma valerolactone (GVL), N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone and mixtures of two or more thereof. In some embodiments of the process, the one or more solvent(s) of the second solvent system is / are selected from the group consisting of gamma valerolactone (GVL), N-bu- tylpyrrolidone (NBP), acetophenone and mixtures of two or more thereof. In some embodiments of the process, the one or more solvent(s) of the second solvent system is / are selected from the group consisting of gamma valerolactone (GVL), N-butylpyrrolidone (NBP) and mixtures of GVL and NBP.

[0133] In some embodiments of the process, the one or more solvent(s) of the second solvent system is / are selected from the group consisting of N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone, dimethyl sulfoxide (DMSO), dihydrolevoglucosenon (Gyrene), cyclohexanone and mixtures of two or more thereof. In some embodiments of the process, the one or more solvents) of the second solvent system is / are selected from the group consisting of N-butylpyrroli- done (NBP), propylenecarbonate, acetophenone, dimethyl sulfoxide (DMSO), dihydrolevoglucosenon (Gyrene) and mixtures of two or more thereof. In some embodiments of the process, the one or more solvent(s) of the second solvent system is / are selected from the group consisting of N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone, dimethyl sulfoxide (DMSO) and mixtures of two or more thereof. In some embodiments of the process, the one or more solvent(s) of the second solvent system is / are selected from the group consisting of N-bu- tylpyrrolidone (NBP), propylenecarbonate, acetophenone and mixtures of two or more thereof. In some embodiments of the process, the one or more solvent(s) of the second solvent system is / are selected from the group consisting of N-butylpyrrolidone (NBP), acetophenone and mixtures of N-butylpyrrolidone (NBP) and acetophenone.

[0134] In some embodiments of the process, the one or more solvent(s) of the second solvent system comprise at least GVL, preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least

[0135] 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are GVL, based on a total weight of the one or more solvent(s) being

[0136] 100 weight-%, more preferably the one solvent is GVL, In some embodiments, contacting in (i) is done at a temperature Ti, which is in the range of from 10 to <170 °C wherein Ti is preferably in the range of from 140 to 160 °C, more preferably in the range of from 150 to 160 °C, or contacting in (i) is done at a temperature T, which is in the range of from 65 to 45 K below the boiling point of the GVL, preferably in the range of from 55 to 45 K below the boiling point of the GVL. The contacting in (i) is preferably done at a pressure in the range of from 800 to 1200 hPa. Preferably, the process is run at autogenous pressure, wherein the autogenous pressure may be higher than the ambient pressure of the surrounding area caused by the steam pressure of GVL at the temperature T at which the process is run. The skilled person can determine and / or adjust said autogenous pressure according to the steam pressure curve of GVL at a certain temperature T. Steam pressure curves of GVL are known to a person skilled in the art. The autogenous pressure may be lowered by purging, e.g. by a purging valve, preferably to a pressure between ambient pressure and lower 2000 hPa, preferably between 1200 hPa and 1800 hPa. Autogenous pressure is the pressure caused by the production system itself in a closed system, e.g. a pressure in the range from 800 to 3000 hPa.

[0137] In some embodiments of the process, the one or more solvent(s) of the second solvent system comprise at least N-butylpyrrolidone, preferably at least 90 weight-% of the one or more solvents), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are N-butylpyrrolidone, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is N-butylpyr- rolidone, In some embodiments, contacting in (i) is done at a temperature Ti, which may be in the range of from 10 to <170 °C wherein Ti preferably may be in the range of from 140 to 160 °C, more preferably in the range of from 150 to 160 °C, or contacting in (i) is done at a temperature T, which may be in the range of from 101 to 81 K below the boiling point of the N-bu- tylpyrrolidone, preferably in the range of from 91 to 81 K below the boiling point of the N-bu- tylpyrrolidone. The contacting in (i) is preferably done at a pressure in the range of from 800 to 1200 hPa. Preferably, the process is run at autogenous pressure, wherein the autogenous pressure may be higher than the ambient pressure of the surrounding area caused by the steam pressure of N-butylpyrrolidone at the temperature T at which the process is run. The skilled person can determine and / or adjust said autogenous pressure according to the steam pressure curve of N-butylpyrrolidone at a certain temperature T. Steam pressure curves of N- butylpyrrolidone are known to a person skilled in the art. The autogenous pressure may be lowered by purging, e.g. by a purging valve, preferably to a pressure between ambient pressure and lower 2000 hPa, preferably between 1200 hPa and 1800 hPa. Autogenous pressure is the pressure caused by the production system itself in a closed system, e.g. a pressure in the range from 800 to 3000 hPa.

[0138] In some embodiments of the process, the one or more solvent(s) of the second solvent system comprise at least propylenecarbonate, preferably at least 90 weight-% of the one or more solvents), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are propylenecarbonate, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is propylenecarbonate. In some embodiments, contacting in (i) is done at a temperature Ti, which may be in the range of from 10 to <170 °C wherein Ti preferably may be in the range of from 140 to 160 °C, more preferably in the range of from 150 to 160 °C or contacting in (i) is done at a temperature T, which may be in the range of from 102 to 82 Kelow the boiling point of the propylenecarbonate, preferably in the range of from 92 to 82 K below the boiling point of the propylenecarbonate. The contacting in (i) is preferably done at a pressure in the range of from 800 to 1200 hPa. Preferably, the process is run at autogenous pressure, wherein the autogenous pressure may be higher than the ambient pressure of the surrounding area caused by the steam pressure of propylenecarbonate at the temperature T at which the process is run. The skilled person can determine and / or adjust said autogenous pressure according to the steam pressure curve of propylenecarbonate at a certain temperature T. Steam pressure curves of propylenecarbonate are known to a person skilled in the art. The autogenous pressure may be lowered by purging, e.g. by a purging valve, preferably to a pressure between ambient pressure and lower 2000 hPa, preferably between 1200 hPa and 1800 hPa. Autogenous pressure is the pressure caused by the production system itself in a closed system, e.g. a pressure in the range from 800 to 3000 hPa.

[0139] In some embodiments of the process, the one or more solvent(s) of the second solvent system comprise at least acetophenone, preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are acetophenone, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is acetophenone. In some embodiments, contacting in (i) is done at a temperature Ti , which may be in the range of from 10 to <170 °C wherein Ti preferably may be in the range of from 140 to 160 °C, more preferably in the range of from 150 to 160 °C or contacting in (i) is done at a temperature T, which may be in the range of from 62 to 42 K below the boiling point of the acetophenone, preferably in the range of from 52 to 42 K below the boiling point of the acetophenone. The contacting in (i) is preferably done at a pressure in the range of from 800 to 1200 hPa. Preferably, the process is run at autogenous pressure, wherein the autogenous pressure may be higher than the ambient pressure of the surrounding area caused by the steam pressure of acetophenone at the temperature T at which the process is run. The skilled person can determine and / or adjust said autogenous pressure according to the steam pressure curve of acetophenone at a certain temperature T. Steam pressure curves of acetophenone are known to a person skilled in the art. The autogenous pressure may be lowered by purging, e.g. by a purging valve, preferably to a pressure between ambient pressure and lower 2000 hPa, preferably between 1200 hPa and 1800 hPa. Autogenous pressure is the pressure caused by the production system itself in a closed system, e.g. a pressure in the range from 800 to 3000 hPa.

[0140] In some embodiments of the process, the one or more solvent(s) of the second solvent system comprise at least dimethyl sulfoxide (DMSO), preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are DMSO, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is DMSO. In some embodiments, contacting in (i) is done at a temperature Ti, which may be in the range of from 10 to <170 °C wherein Ti preferably may be in the range of from 140 to 160 °C, more preferably in the range of from 150 to 160 °C or contacting in (i) is done at a temperature T, which may be in the range of from 49 to 29 K below the boiling point of the DMSO, preferably in the range of from 39 to 29 K below the boiling point of the DMSO. The contacting in (i) is preferably done at a pressure in the range of from 800 to 1200 hPa. Preferably, the process is run at autogenous pressure, wherein the autogenous pressure may be higher than the ambient pressure of the surrounding area caused by the steam pressure of DMSO at the temperature T at which the process is run. The skilled person can determine and / or adjust said autogenous pressure according to the steam pressure curve of DMSO at a certain temperature T. Steam pressure curves of DMSO are known to a person skilled in the art. The autogenous pressure may be lowered by purging, e.g. by a purging valve, preferably to a pressure between ambient pressure and lower 2000 hPa, preferably between 1200 hPa and 1800 hPa. Autogenous pressure is the pressure caused by the production system itself in a closed system, e.g. a pressure in the range from 800 to 3000 hPa. In some embodiments of the process, the one or more solvent(s) of the second solvent system comprise at least dihydrolevoglucosenon (Cyrene), preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are Cyrene, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is Cyrene. In some embodiments, contacting in (i) is done at a temperature Ti, which may be in the range of from 10 to <170 °C wherein Ti preferably may be in the range of from 140 to 160 °C, more preferably in the range of from 150 to 160 °C or contacting in (i) is done at a temperature T, which may be in the range of from 86 to 66 K below the boiling point of the Cyrene, preferably in the range of from 76 to 66 K below the boiling point of the Cyrene. The contacting in (i) is preferably done at a pressure in the range of from 800 to 1200 hPa. Preferably, the process is run at autogenous pressure, wherein the autogenous pressure may be higher than the ambient pressure of the surrounding area caused by the steam pressure of Cyrene at the temperature T at which the process is run. The skilled person can determine and / or adjust said autogenous pressure according to the steam pressure curve of Cyrene at a certain temperature T. Steam pressure curves of Cyrene are known to a person skilled in the art. The autogenous pressure may be lowered by purging, e.g. by a purging valve, preferably to a pressure between ambient pressure and lower 2000 hPa, preferably between 1200 hPa and 1800 hPa. Autogenous pressure is the pressure caused by the production system itself in a closed system, e.g. a pressure in the range from 800 to 3000 hPa.

[0141] In some embodiments of the process, the one or more solvent(s) of the second solvent system comprise at least cyclohexanone, preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are cyclohexanone, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is cyclohexanone. In some embodiments, contacting in (i) is done at a temperature Ti, which may be in the range of from 10 to <170 °C wherein Ti preferably may be in the range of from 140 to 155 °C, more preferably in the range of from 145 to 150 °C or contacting in (i) is done at a temperature T, which may be in the range of from 16 to 1 K below the boiling point of the cyclohexanone, preferably in the range of from 11 to 6 K below the boiling point of the cyclohexanone. The contacting in (i) is preferably done at a pressure in the range of from 800 to 1200 hPa. Preferably, the process is run at autogenous pressure, wherein the autogenous pressure may be higher than the ambient pressure of the surrounding area caused by the steam pressure of cyclohexanone at the temperature T at which the process is run. The skilled person can determine and / or adjust said autogenous pressure according to the steam pressure curve of cyclohexanone at a certain temperature T. Steam pressure curves of cyclohexanone are known to a person skilled in the art. The autogenous pressure may be lowered by purging, e.g. by a purging valve, preferably to a pressure between ambient pressure and lower 2000 hPa, preferably between 1200 hPa and 1800 hPa. Autogenous pressure is the pressure caused by the production system itself in a closed system, e.g. a pressure in the range from 800 to 3000 hPa.

[0142] In some embodiments of the process, the second solvent system comprises in least 90 weight- %, preferably at least 95 weight-% the same solvent(s) in the same amounts as the first solvent system, more preferably first solvent system and second solvent system are the same. Preferably, first and second solvent system are then selected from the group consisting of gamma valerolactone (GVL), N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone, dimethyl sulfoxide (DMSO), dihydrolevoglucosenon (Gyrene) and mixtures of two or more thereof. More preferably, first and second solvent system each comprises at least 90 weight-%, more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-% of one solvent, more preferably of one and the same solvent selected from the group consisting of gamma valerolactone (GVL), N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone, dimethyl sulfoxide (DMSO) and dihydrolevoglucosenon (Gyrene). Having identical solvent(s) as first and second solvent system is of advantage especially when the process is carried out according to embodiments with steps (i’.1) and (i’.2), in that still further savings in view of equipment required and solvent(s) used are possible.

[0143] Colorant

[0144] In some embodiments of the process, the colorant is selected from the group consisting of dye and optical brightener and mixtures of dye and optical brightener.

[0145] A “colorant” is a substance that cause the change of color impression of a material. This comprises dyes, which absorb wavelength intervals of visible light (400 to 780 nm) and optical brighteners, which amplify the light emission of a material through UV light adsorption and emittance of visible light (through fluorescence), i.e. an optical brightener converts radiation that is not visible to the human eye (<400nm) into visible fluorescence radiation of the blue-red spectral range (400 to 600 nm). Colorants usable or used for changing the color impression of polymeric materials are known to the skilled person. In the context of the present invention, the term “dye” means any kind of dye such as dye, pigment, dispersion, wherein a dye is, for example, one or more selected from the group consisting of acid dye, basic dye, direct dye, disperse dye, azoic dye, food dye, solvent dye, organic dye, inorganic pigment, organic pigment, disperse ink, reactive ink, oxidation dye, reactive dye, sulfur dye, mordant dye and vat dye. The term “optical brightener” comprises optical brightening agents, fluorescent brightening agents, and fluorescent whitening agents.

[0146] Overviews of colorants for polymeric materials can be found, for example, in “Dyes and Pigments” Metin Agikyildiz, Kubra Gunes, Ahmet Gurses Springer, 2016 (ISBN: 10 : 3319338900); Industrial Organic Pigments - Klaus Hunger, Thomas Heber, Martin II. Schmidt, Friedrich Reisinger, Stefan Wanne Wiley-VCH, 4thedition, 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: Syntheses, Properties, and Applications of Organic Dyes and Pigments. 3rdedition. 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: Lehrbuch der Textilchemie. ein- schl. 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).

[0147] In some embodiments of the process, depleted in colorant regarding the polyalkylene terephthalate based polymer obtained means that the L*a*b* values of the polyalkylene terephthalate based polymer which is depleted in colorant compared to the polymeric material provided in (a), change in that: the absolute value of a* changes, preferably by at least 0.2; and / or, preferably and, the absolute value of b* changes, preferably by at least 0.2; and / or, preferably and, the L* value increases, preferably by at least 4, each compared to the L*a*b* values of the colored polymeric material provided in (a), wherein L*a*b* values are determined according to DIN 5033 and DIN EN ISO 11664-1.6.

[0148] The expression “irrespective of the color” means that, even if analytics are normally done for materials of each color separately, the definitions given above apply for single-colored polymeric materials, but also for polymeric materials having a plurality of colors and mixtures of pieces of polymeric materials, wherein each piece has its own color or its own color mix.

[0149] The condition of being “depleted in colorant”, which is expressed above based on quantitative L*a*b* values is also identifiable visually by the eye: The polymeric material provided in (a) has a certain color, wherein the polymeric material obtained, preferably obtained from (ii), (iii) or (iv) as described herein below is lighter and whiter respectively. This applies especially for all colorants not being optical brighteners. Depleted in colorant regarding the polymeric material obtained means, especially with respect to optical brighteners being the colorant, that the intensity of emitted fluorescence radiation (emission), preferably in the range of from 400 to 600 nm, is reduced for the polymeric material obtained in (s) when irradiated with light with a wavelength in the range of from 250 to 400 nm compared to the intensity of emitted fluorescence radiation (emission), preferably in the range of from 400-600 nm, of the polymeric material provided in

[0150] (a).

[0151] Methods for determination of the intensity of emitted fluorescence radiation are known to the skilled person, for example, the determination can be made visually by using an UV lamp, by fluorescence determination or determination of quantum yield.

[0152] In some embodiments the process comprises

[0153] (ii) separating the polyalkylene terephthalate based polymer, which is depleted in colorant from the second solvent system, which is enriched in colorant of (i).

[0154] According to these embodiments, the process preferably comprises:

[0155] (a) providing the colored polymeric material comprising polyalkylene terephthalate based polymer and providing a first and a second solvent system;

[0156] (b) contacting the colored polymeric material with a first solvent system at a temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the first solvent in the solvent system, which has the lowest boiling point, thereby obtaining a first solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer;

[0157] (c) separating polyalkylene terephthalate based polymer from the first solvent system obtained in (b), thereby re-obtaining polyalkylene terephthalate based polymer comprising (c.1) optionally after heated filtration, cooling the first solvent system obtained in (b) which is enriched in dissolved polyalkylene terephthalate based polymer compared to the first solvent system provided in (a) to a temperature below 160°C, preferably below 150°C, more preferably below 140°C, more preferably below 120°C;

[0158] (c.2) obtaining a precipitated polyalkylene terephthalate based polymer and a first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer;

[0159] (i’.1) separating the precipitated polyalkylene terephthalate based polymer obtained in (c.2) from the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer, thereby obtaining a precipitated polyalkylene terephthalate based polymer and the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer;

[0160] (i’.2) contacting the precipitated polyalkylene terephthalate based polymer of (i’.1) with a second solvent system at a temperature Ti , which is < 170 °C, thereby obtaining a second solvent system, which is enriched in colorant compared to the second solvent system provided in (a), and a polyalkylene terephthalate based polymer, which is depleted in colorant compared to the colored polymeric material provided in (a); and

[0161] (ii) separating the polyalkylene terephthalate based polymer, which is depleted in colorant from the second solvent system, which is enriched in colorant of (i).

[0162] As described above, steps (i’.1) and (i’.2) are preferably carried out within the same device, such as a filtration device suitable for heated filtration at an adjustable temperature. A process with steps (i’.1) and (i’.2) offers the advantage that less process steps and less equipment are required compared to a process, wherein steps (d), (e) and step (i) are carried out separately or compared to a process wherein a colored polymeric material has to be initially discolored, before dissolution. Preferably, step (i’.2) follows directly after step (i’.1), i.e. no intermediate step is carried out between step (i’.1) and step (i’.2) and, as indicated above, both steps (i’.1) and (i’.2) are carried out within the same device.

[0163] The separation in (ii) is done by methods and means known to the skilled person, especially solid-liquid separation methods such as filtration, for example, heated pressure filtration, sedimentation or centrifugation (see Handbuch der mechanischen Fest-Flussig-Trennung Taschen- buch - 29. April 2004 von Klaus Luckert (Herausgeber)). Colorants remain at least partially in the separated solvent system obtained in (b. ii’).

[0164] Washing

[0165] In some embodiments the process comprises

[0166] (iii) washing the separated polyalkylene terephthalate based polymer of (ii) with a washing solvent, thereby obtaining a washed polyalkylene terephthalate based polymer, which is depleted in colorant compared to the polymeric material provided in (a).

[0167] According to these embodiments, the process preferably comprises:

[0168] (a) providing the colored polymeric material comprising polyalkylene terephthalate based polymer and providing a first and a second solvent system; (b) contacting the colored polymeric material with a first solvent system at a temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the first solvent in the solvent system, which has the lowest boiling point, thereby obtaining a first solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer;

[0169] (c) separating polyalkylene terephthalate based polymer from the first solvent system obtained in (b), thereby re-obtaining polyalkylene terephthalate based polymer comprising (c.1) optionally after heated filtration, cooling the first solvent system obtained in (b) which is enriched in dissolved polyalkylene terephthalate based polymer compared to the first solvent system provided in (a) to a temperature below 160°C, preferably below 150°C, more preferably below 140°C, more preferably below 120°C;

[0170] (c.2) obtaining a precipitated polyalkylene terephthalate based polymer and a first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer;

[0171] (i’.1) separating the precipitated polyalkylene terephthalate based polymer obtained in (c.2) from the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer, thereby obtaining a precipitated polyalkylene terephthalate based polymer and the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer;

[0172] (i’.2) contacting the precipitated polyalkylene terephthalate based polymer of (i’.1) with a second solvent system at a temperature Ti, which is < 170 °C, thereby obtaining a second solvent system, which is enriched in colorant compared to the second solvent system provided in (a), and a polyalkylene terephthalate based polymer, which is depleted in colorant compared to the colored polymeric material provided in (a);

[0173] (ii) separating the polyalkylene terephthalate based polymer, which is depleted in colorant from the second solvent system, which is enriched in colorant of (i); and

[0174] (iii) washing the separated polyalkylene terephthalate based polymer of (ii) with a washing solvent, thereby obtaining a washed polyalkylene terephthalate based polymer, which is depleted in colorant compared to the polymeric material provided in (a).

[0175] As described above, steps (i’.1) and (i’.2) are preferably carried out within the same device, such as a filtration device suitable for heated filtration at an adjustable temperature. A process with steps (i’.1) and (i’.2) offers the advantage that less process steps and less equipment are required compared to a process, wherein steps (d), (e) and step (i) are carried out separately or compared to a process wherein a colored polymeric material has to be initially discolored, before dissolution. Preferably, step (i’.2) follows directly after step (i’.1), i.e. no intermediate step is carried out between step (i’.1) and step (i’.2) and, as indicated above, both steps (i’.1) and (i’.2) are carried out within the same device. Drying

[0176] In some embodiments the process comprises

[0177] (iv) drying the separated polyalkylene terephthalate based polymer of (ii) and / or the washed polyalkylene terephthalate based polymer obtained in (iii).

[0178] According to these embodiments, the process preferably comprises:

[0179] (a) providing the colored polymeric material comprising polyalkylene terephthalate based polymer and providing a first and a second solvent system;

[0180] (b) contacting the colored polymeric material with a first solvent system at a temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the first solvent in the solvent system, which has the lowest boiling point, thereby obtaining a first solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer;

[0181] (c) separating polyalkylene terephthalate based polymer from the first solvent system obtained in (b), thereby re-obtaining polyalkylene terephthalate based polymer comprising (c.1) optionally after heated filtration, cooling the first solvent system obtained in (b) which is enriched in dissolved polyalkylene terephthalate based polymer compared to the first solvent system provided in (a) to a temperature below 160°C, preferably below 150°C, more preferably below 140°C, more preferably below 120°C;

[0182] (c.2) obtaining a precipitated polyalkylene terephthalate based polymer and a first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer;

[0183] (i’.1) separating the precipitated polyalkylene terephthalate based polymer obtained in (c.2) from the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer, thereby obtaining a precipitated polyalkylene terephthalate based polymer and the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer;

[0184] (i’.2) contacting the precipitated polyalkylene terephthalate based polymer of (i’.1) with a second solvent system at a temperature Ti, which is < 170 °C, thereby obtaining a second solvent system, which is enriched in colorant compared to the second solvent system provided in (a), and a polyalkylene terephthalate based polymer, which is depleted in colorant compared to the colored polymeric material provided in (a);

[0185] (ii) separating the polyalkylene terephthalate based polymer, which is depleted in colorant from the second solvent system, which is enriched in colorant of (i); (iii) washing the separated polyalkylene terephthalate based polymer of (ii) with a washing solvent, thereby obtaining a washed polyalkylene terephthalate based polymer, which is depleted in colorant compared to the polymeric material provided in (a); and

[0186] (iv) drying the separated polyalkylene terephthalate based polymer of (ii) and / or the washed polyalkylene terephthalate based polymer obtained in (iii).

[0187] As described above, steps (i’.1) and (i’.2) are preferably carried out within the same device, such as a filtration device suitable for heated filtration at an adjustable temperature. A process with steps (i’.1) and (i’.2) offers the advantage that less process steps and less equipment are required compared to a process, wherein steps (d), (e) and step (i) are carried out separately or compared to a process wherein a colored polymeric material has to be initially discolored, before dissolution. Preferably, step (i’.2) follows directly after step (i’.1), i.e. no intermediate step is carried out between step (i’.1) and step (i’.2) and, as indicated above, both steps (i’.1) and (i’.2) are carried out within the same device.

[0188] Washing in step (iii) is preferably done with a solvent system having features (s2.1),(s2.2) and (s2.3) as described above or a solvent system having features (s2.1a), (s2.2a) and (s2.3a) as described above. In some embodiments, washing is done with a solvent selected from the group consisting of methanol, ethanol, propanol, isopropanol, acetonitrile, ethyl acetate, acetone, water or a mixture of two or more of these solvents. In some embodiments, the washing in optional step (iii) is done with a solvent selected from the group consisting of methanol, ethanol, propanol, isopropanol, acetonitrile, ethyl acetate, acetone, water, GVL, or a mixture of two or more of these solvents. Drying in step (iv) is preferably done under one or more conditions selected from the group consisting of a pressure in the range of from 1 to 1013 mbar; a temperature in the range of from 50 to 210 °C, preferably in the range of from 60 to 180°C, more preferably in the range of from 80 to 160 °C; drying time in the range of from 30 minutes to 24 hours; drying in an atmosphere comprising nitrogen, preferably in an atmosphere having at least 90 volume-%, more preferably 95 volume-%, more preferably at least 98 volume-% nitrogen. Drying is done by one or more methods selected from the group consisting of contact drying, convection drying and radiation drying.

[0189] In some embodiments of the process, the re-obtained polyalkylene terephthalate based polymer of any one of steps (i), (ii), (iii) or (iv) has a number average molecular weight Mn, which is greater or at least equal to the Mn of the polyalkylene terephthalate based polymer comprised in the polymeric material provided in (a).

[0190] In some embodiments of the process, the re-obtained polyalkylene terephthalate based polymer of any one of steps (i), (ii), (iii) or (iv) has a dispersity Mw / Mn (Mass average molecular weight Mw divided by number average molecular weight Mn) in the range of from 70 to 95 %, preferably in the range of from 75 to 90 % of the dispersity Mw / Mn of the polyalkylene terephthalate based polymer comprised in the polymeric material provided in (a) (100%).

[0191] In some embodiments, the process comprises recycling separated solvent system obtained in one or more of the process steps described above back into the process, optionally after one or more work-up step(s).

[0192] 2ndaspect - polyalkylene terephthalate based polymer depleted in colorant

[0193] A second aspect of the invention is directed to polyalkylene terephthalate based polymer, which is depleted in colorant, obtained or obtainable from the process of the first aspect, preferably obtained or obtainable from any one of steps (i), (ii), (iii) or (iv). All details and embodiments disclosed in the section above related to the first aspect apply also for the second aspect.

[0194] 3rdaspect - Use

[0195] A third aspect of the invention relates to the use of the polyalkylene terephthalate based polymer, which is depleted in colorant of the second aspect for textile applications, fiber applications, packaging applications or plastic applications, preferably for the production of food packaging, beverage packaging, clothing and foot wear. All details and embodiments disclosed in the section above related to the first aspect apply also for the third aspect.

[0196] Preferably, the polyalkylene terephthalate based polymer is used for: a part of a car; preferably cylinder head cover, engine cover, housing for charge air cooler, charge air cooler flap, intake pipe, intake manifold, connector, gear wheel, fan wheel, cooling water box, housing, housing part for heat exchanger, coolant cooler, charge air cooler, thermostat, water pump, radiator, fastening part, part of battery system for electromobility, dashboard, steering column switch, seat, headrest, center console, transmission component, door module, A, B, C or D car pillar cover, spoiler, door handle, exterior mirror, windscreen wiper, windscreen wiper protection housing, decorative grill, cover strip, roof rail, window frame, sunroof frame, antenna panel, headlight and taillight, engine cover, cylinder head cover, intake manifold, airbag, cushion, or coating; a cloth; preferably shirt, trousers, pullover, boot, shoe, shoe sole, tight or jacket; an electrical part; preferably electrical or electronic passive or active component, circuit board, printed circuit board, housing component, foil, line, switch, plug, socket, distributor, relay, resistor, capacitor, inductor, bobbin, lamp, diode, LED, transistor, connector, regula- tor, integrated circuit (I C) , processor, controller, memory, sensor, microswitch, microbutton, semiconductor, reflector housing for light-emitting diodes (LED), fastener for electrical or electronic component, spacer, bolt, strip, slide-in guide, screw, nut, film hinge, snap hook (snap-in), or spring tongue; a consumer, agricultural product or pharmaceutical product; preferably tennis string, climbing rope, bristle, brush, artificial grass, 3D printing filament, grass trimmer, zipper, hook and loop fastener, paper machine clothing, extrusion coating, fishing line, fishing net, offshore line and rope, vial, syringe, ampoule, bottle, sliding element, spindle nut, chain conveyor, plain bearing, roller, wheel, gear, roller, ring gear, screw and spring dampers, hose, pipeline, cable sheathing, socket, switch, cable tie, fan wheel, carpet, box or bottle for cosmetics, mattress, cushion, insulation, detergent, dishwasher tabs or powder, shampoo, body wash, shower gel, soap, fertilizer, fungicide, or pesticide; a packaging for the food industry; preferably mono- or multi-layer blown film, cast film (mono- or multi-layer), biaxially stretched film, or laminating film; or a part of a construction; preferably a rotor blade, insulating material, frame, housing, wall, coating, or separating wall.

[0197] In the third aspect, the invention is also directed to a method for preparing a textile or a packaging comprising

[0198] (A) providing polyalkylene terephthalate based polymer which is depleted in colorant, preferably polyalkylene terephthalate based polymer of the second aspect;

[0199] (B) preparing a textile or a packaging from the polymeric material provided in (A).

[0200] Preferably in (B) a part of a car; preferably cylinder head cover, engine cover, housing for charge air cooler, charge air cooler flap, intake pipe, intake manifold, connector, gear wheel, fan wheel, cooling water box, housing, housing part for heat exchanger, coolant cooler, charge air cooler, thermostat, water pump, radiator, fastening part, part of battery system for electromobility, dashboard, steering column switch, seat, headrest, center console, transmission component, door module, A, B, C or D car pillar cover, spoiler, door handle, exterior mirror, windscreen wiper, windscreen wiper protection housing, decorative grill, cover strip, roof rail, window frame, sunroof frame, antenna panel, headlight and taillight, engine cover, cylinder head cover, intake manifold, airbag, cushion, or coating; a cloth; preferably shirt, trousers, pullover, boot, shoe, shoe sole, tight or jacket; an electrical part; preferably electrical or electronic passive or active component, circuit board, printed circuit board, housing component, foil, line, switch, plug, socket, distributor, relay, resistor, capacitor, inductor, bobbin, lamp, diode, LED, transistor, connector, regula- tor, integrated circuit (IC), processor, controller, memory, sensor, microswitch, microbutton, semiconductor, reflector housing for light-emitting diodes (LED), fastener for electrical or electronic component, spacer, bolt, strip, slide-in guide, screw, nut, film hinge, snap hook (snap-in), or spring tongue; a consumer, agricultural product or pharmaceutical product; preferably tennis string, climbing rope, bristle, brush, artificial grass, 3D printing filament, grass trimmer, zipper, hook and loop fastener, paper machine clothing, extrusion coating, fishing line, fishing net, offshore line and rope, vial, syringe, ampoule, bottle, sliding element, spindle nut, chain conveyor, plain bearing, roller, wheel, gear, roller, ring gear, screw and spring dampers, hose, pipeline, cable sheathing, socket, switch, cable tie, fan wheel, carpet, box or bottle for cosmetics, mattress, cushion, insulation, detergent, dishwasher tabs or powder, shampoo, body wash, shower gel, soap, fertilizer, fungicide, or pesticide; a packaging for the food industry; preferably mono- or multi-layer blown film, cast film (mono- or multi-layer), biaxially stretched film, or laminating film; or a part of a construction; preferably a rotor blade, insulating material, frame, housing, wall, coating, or separating wall, is prepared.

[0201] 4thaspect - process comprising conversion of re-obtained polyalkylene terephthalate based polymer

[0202] A fourth aspect of the invention is directed to a process, preferably according to the first aspect, comprising the further step: converting the re-obtained polyalkylene terephthalate based polymer obtained or obtainable by the process according to the first aspect to obtain a polymer product.

[0203] All details and embodiments disclosed above for the first aspect apply also for the fourth aspect.

[0204] 5thaspect - Process comprising converting the residue

[0205] A fifth aspect of the invention is directed to a process, preferably according to the first aspect, comprising the further step: converting the residue comprising at least one insoluble polymer selected from PP, PE, PA, natural polymer, viscose and linen obtainable by or obtained by the process according to the first aspect, preferably obtained or obtainable from step (b.2), to obtain one or more monomer, polymer or polymer product.

[0206] All details and embodiments disclosed above for the first aspect apply also for the fifth aspect. Preferably, the monomer is a di- or polyol; preferably butandiol; aldehyde; preferably formaldehyde; di- or polyisocyanate; preferably methylene diphenyl diisocyanate (MDI), polymeric methylene diphenyl diisocyanate (pMDI), toluene diisocyanate (TDI), hexamethylenediisocyanate (HDI) or isophoronediisocyanate (IPDI); amide; preferably caprolactam; alkene; preferably styrene, ethene and norbornene; alkyne, (di)ester; preferably methyl methacrylate; mono or diacid; preferably adipic acid or terephthalic acid; diamine; preferably hexamethylenediamine, nonanediamine; or sulfones; preferably 4,4'-dichlorodiphenyl sulfone.

[0207] Preferably, the polymer is and / or the polymer product comprises polyamide (PA); preferably PA 6 or PA 66; polyisocyanate polyaddition product; preferably polyurethane (Pll), thermoplastic polyurethane (TPU), polyurea or polyisocyanurate (PIR); low-density polyethylene (LDPE), high- density polyethylene (HDPE), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyvinyl acetate (PVA), polystyrene (PS), poly acrylonitrile butadiene styrene (ABS), poly styrene acrylonitrile (SAN), poly acrylate styrene acrylonitrile (ASA), polytetrafluoroethylene (PTFE), poly(methyl acrylate) (PMA), poly(methyl methacrylate) (PMMA), polybutadiene (BR, PBD), poly(cis-1,4-isoprene), poly(trans-1,4-isoprene), polyoxymethylene (POM), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polybutylene adipate coterephthalate (PBAT), polyester (PES), polyether sulfone (PESLI), polyhydroxyalkanoate (PHA), poly-3-hy- droxybutyrate (P3HB), poly-4-hydroxybutyrate (P4HB), polyhydroxyvalerate (PHV), polyhydroxyhexanoate (PHH), polyhydroxyoctanoate (PHO), polylactic acid (PLA), polysulfone (PSU), polyphenylene sulfone (PPSLI), polycarbonate (PC), polyether ether ketone (PEEK), poly(p-phe- nylene oxide) (PPO), poly(p-phenylene ether) (PPE); or copolymer or mixture thereof.

[0208] Preferably, the polymer and / or the polymer product is / are or is / are a part of: a part of a car; preferably cylinder head cover, engine cover, housing for charge air cooler, charge air cooler flap, intake pipe, intake manifold, connector, gear wheel, fan wheel, cooling water box, housing, housing part for heat exchanger, coolant cooler, charge air cooler, thermostat, water pump, radiator, fastening part, part of battery system for electromobility, dashboard, steering column switch, seat, headrest, center console, transmission component, door module, A, B, C or D car pillar cover, spoiler, door handle, exterior mirror, windscreen wiper, windscreen wiper protection housing, decorative grill, cover strip, roof rail, window frame, sunroof frame, antenna panel, headlight and taillight, engine cover, cylinder head cover, intake manifold, airbag, cushion, or coating; a cloth; preferably shirt, trousers, pullover, boot, shoe, shoe sole, tight or jacket; an electrical part; preferably electrical or electronic passive or active component, circuit board, printed circuit board, housing component, foil, line, switch, plug, socket, distributor, relay, resistor, capacitor, inductor, bobbin, lamp, diode, LED, transistor, connector, regula- tor, integrated circuit (IC), processor, controller, memory, sensor, microswitch, microbutton, semiconductor, reflector housing for light-emitting diodes (LED), fastener for electrical or electronic component, spacer, bolt, strip, slide-in guide, screw, nut, film hinge, snap hook (snap-in), or spring tongue; a consumer, agricultural product or pharmaceutical product; preferably tennis string, climbing rope, bristle, brush, artificial grass, 3D printing filament, grass trimmer, zipper, hook and loop fastener, paper machine clothing, extrusion coating, fishing line, fishing net, offshore line and rope, vial, syringe, ampoule, bottle, sliding element, spindle nut, chain conveyor, plain bearing, roller, wheel, gear, roller, ring gear, screw and spring dampers, hose, pipeline, cable sheathing, socket, switch, cable tie, fan wheel, carpet, box or bottle for cosmetics, mattress, cushion, insulation, detergent, dishwasher tabs or powder, shampoo, body wash, shower gel, soap, fertilizer, fungicide, or pesticide; a packaging for the food industry; preferably mono- or multi-layer blown film, cast film (mono- or multi-layer), biaxially stretched film, or laminating film; or a part of a construction; preferably a rotor blade, insulating material, frame, housing, wall, coating, or separating wall.

[0209] Preferably, the content of the at least one insoluble polymer selected from PP, PE, PA, natural polymer, viscose and linen in the polymer and / or polymer product is 1 weight-% or more, preferably 2 weight-% or more, more preferably 5 weight-% or more, more preferably 15 weight-% or more, more preferably 30 weight-% or more, more preferably 40 weight-% or more, more preferably 60 weight-% or more, more preferably 80 weight-% or more, more preferably 90 weight-% or more, more preferably 95 weight-% or more; and / or the content of the at least one insoluble polymer selected from PP, PE, PA, natural polymer, viscose and linen in the polymer and / or polymer product is 100 weight-% or less, preferably 95 weight-% or less, more preferably 90 weight-% or less, more preferably 50 weight-% or less, more preferably 25 weight-% or less, more preferably 10 weight-% or less; and preferably the content is determined based on identity preservation and / or segregation and / or mass balance and / or book and claim chain of custody models, preferably based on mass balance, preferably the International Sustainability and Carbon Certification (ISCC) standard.

[0210] The converting steps to obtain the monomer, polymer or polymer product may comprise one or more synthesis steps and can be performed by conventional synthesis and technics well known to a person skilled in the art. Independent of the person skilled in the art to assess novelty and inventive step of the independent claim(s), the person skilled in the art to perform the converting step(s) is preferably from the technical field(s) pyrolysis, gasification, remonomerization, depolymerization, synthesis, production of monomers, polymers and polymer compounds, and / or its further processing (e.g. extrusion, injection molding). Examples of the step(s) of the conversion is / are described in “Industrial Organic Chemistry”, 3. volume, Wiley-VCH, 1997, ISBN: 978-3- 527-28838-0, „Kunststoffhandbuch“, 11 volumes in 17 sub-volumes, Carl Hanser Verlag; especially volume 6, „Polyamide“, 1. edition, 1966, volume 7, ..Polyurethane", 3. edition, 1993, and volume 8, “Polyester”, 2. edition 1973; “Industrial Organic Chemistry”, 3. volume, Wiley-VCH, 1997, ISBN: 978-3-527-28838-0, “Injection Molding Reference Guide, 4th edition, CreateSpace Independent Publishing Platform, 2011 , ISBN: 978-1466407824, EP0989146 A1 , EP1460094 A1 , WO 2006034800 A1 , EP 1529792 A1 , WO 2006042674 A1 , EP 0364854 A2, US 5506275 A, EP 0897402 A1 , WO 2015082316 A1 , WO 2021021855 A1 , WO 2021126938 A1 , WO 2021021902 A1 , WO 2021092311 A1 , WO 2008155271 A1 , WO 2013139827 A1 , each of which is incorporated herein by reference.

[0211] The present invention is further illustrated by the following embodiments and combinations of embodiments as indicated by the respective dependencies and back-references. In particular, it is noted that in each instance where a range of embodiments is mentioned, for example in the context of a term such as "The ... of any of embodiments 1 to 4", every embodiment in this range is meant to be explicitly disclosed for the skilled person, i.e. the wording of this term is to be understood by the skilled person as being synonymous to "The ... of any of embodiments 1 , 2, 3, and 4".

[0212] 1 . A process for recovery of a polyalkylene terephthalate based polymer from a colored polymeric material, the process comprising:

[0213] (a) providing the colored polymeric material comprising polyalkylene terephthalate based polymer and providing a first and a second solvent system;

[0214] (b) contacting the colored polymeric material with a first solvent system at a temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the first solvent in the solvent system, which has the lowest boiling point, thereby obtaining a first solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer;

[0215] (c) separating polyalkylene terephthalate based polymer from the first solvent system obtained in (b), thereby re-obtaining polyalkylene terephthalate based polymer; wherein the first solvent system comprises one or more solvent(s), wherein (s1.1 ) the solvent system has Hansen solubility parameters with respect to

[0216] - energy from dispersion forces between molecules (bDss),

[0217] - energy from dipolar intermolecular force between molecules (bPss) and

[0218] - energy from hydrogen bonds between molecules (5HSs), which fulfill equitation 1

[0219] (8.8)2> 4(6Dss-20)2+ (5PSS-11.8)2+ (5Hss-4.5)2

[0220] [equitation 1];

[0221] (s1.2) each solvent of the solvent system has a boiling point at 1013 hPa of at least 160 °C; and

[0222] (s1.3) solvents having a functional group selected from the group consisting of hydroxyl (OH), amino (NH2), carboxyl (COOH), and thiol (SH) are excluded;

[0223] (i) contacting the re-obtained polyalkylene terephthalate based polymer of (c) with a second solvent system at a temperature T1 , which is < 170 °C, thereby obtaining a second solvent system, which is enriched in colorant compared to the second solvent system provided in (a), and a polyalkylene terephthalate based polymer, which is depleted in colorant compared to the colored polymeric material provided in (a); wherein the second solvent system comprises one or more solvents, wherein (s2.1) the solvent system has Hansen solubility parameters with respect to

[0224] - energy from dispersion forces between molecules (5DSS),

[0225] - energy from dipolar intermolecular force between molecules (5PSS) and

[0226] - energy from hydrogen bonds between molecules (5HSS), which fulfill equitation 2

[0227] (11)2> 4(6DSS-17.5)2+ (6Pss-7.5)2+ (5Hss-7.5)2

[0228] [equitation 2];

[0229] (s2.2) each solvent of the solvent system has a boiling point at 1013 hPa of at least 150 °C. The process of embodiment 1 , wherein contacting in (b) is done at a temperature in the range of from 160 °C to the temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the solvent in the solvent system, which has the lowest boiling point. The process of embodiment 1 or 2, wherein at least 90 weight-%, preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, of the first solvent system consist of two or more solvent(s), wherein the respective mixture fulfill(s) equitation 1. The process of embodiment 1 tor 2, wherein at least 90 weight-%, preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, of the first solvent system consist of one solvent, which fulfills equitation 1. The process of any one of embodiments 1 to 4, wherein the one or more solvent(s) of the first solvent system is / are selected from the group consisting of N,N-dimethylbenzamide, N,N-dimethylphenylacetamide, 1,4-benzoquinone, acetophenone, dimethyl terephthalate, 1 ,3,5-trimethoxybenzene, 2-phenylacetophenone, N-methylcaprolactam, methylbenzoate, methyl-4-methoxybenzoate, butylene carbonate, propylene-glycol-dibenzoate, N-ethylpyr- rolidone, benzophenone, di-benzyl malonate, N-ethyl-caprolactam, methyl 2-(5-oxotetra- hydrofuran-3-yl)acetate (FAME), propiophenone, N-methoxypropyl-pyrrolidone, 1,4-cyclo- hexanedione, cyclohexane-carbonate, N-methoxyethyl-pyrrolidone, N,N-diethylphenyla- cetamide, phenyl acetate, 1-(2-hydroxyethyl)pyrrolidin-2-one acetate (HEPAc), N,N-dieth- ylbenzamide, isopropyl-benzoate, cyclohexyl phenyl ketone, phenylacetic acid ethylester, phenylacetat, N-methyl-morpholine, benzyl-propionate, benzylacetate, Neopentyl-glycol- dibenzoate, retrahydrofurfuryl acetate, N-methyl-imidazole, benzyl butyrate, 2-pyrrolidone, 2-phenoxyethanol propionate, 2-phenoxyethyl isobutyrate, N,N-dipropylbenzamide, N,N- dimethylacetamide, N,N-diethylacetamide, dihydrolevoglucosenon (Cyrene), propylenecarbonate, caprolactone, dimethylisosorbide, N-butylpyrrolidone, t-butylpyrrolidone, me- thyl-1-methyl-5-oxopyrrolidine-3-carboxylate (MMOC), gamma-valerolactone (GVL), delta- valerolactone, gamma butyrolactone, methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate (Rhodiasolv Polarclean), caprolactam, phen ethyl acetate, methyl phenylacetate, benzyl benzoate, N,N-dimethyllactamide (Agnique AMD 3L), and dimethyl sulfoxide (DMSO). The process of any one of embodiments 1 to 5, wherein the one or more solvent(s) of the first solvent system is / are selected from the group consisting of dihydrolevoglucosenon (Cyrene), propylenecarbonate, caprolactone, dimethylisosorbide, N-butylpyrrolidone, t-bu- tylpyrrolidone, methyl-1-methyl-5-oxopyrrolidine-3-carboxylate (MMOC), gamma- valerolactone (GVL), delta-valerolactone, gamma butyrolactone, methyl 5-(dimethyla- mino)-2-methyl-5-oxopentanoate (RhodiasolvOPolarclean), caprolactam, phenethyl acetate, methyl phenylacetate, benzyl benzoate, phen yl benzoate, methyl benzoate, propyl benzoate, and dimethyl sulfoxide (DMSO). The process of any one of embodiments 1 to 6, wherein the one or more solvent(s) of the first solvent system is / are selected from the group consisting of propylenecarbonate, N- butylpyrrolidone, t-butylpyrrolidone, methyl-1-methyl-5-oxopyrrolidine-3-carboxylate (MMOC), Delta-valerolactone, gamma butyrolactone, methyl 5-(dimethylamino)-2-methyl- 5-oxopentanoate (RhodiasolvOPolarclean), caprolactam, phenethyl acetate, methyl phenylacetate, benzyl benzoate, phenyl benzoate, methyl benzoate, propyl benzoate and GVL. 8. The process of any one of embodiments 1 to 7, wherein the one or more solvent(s) of the first solvent system is / are selected from the group consisting of propylenecarbonate, N- butylpyrrolidone, t-butylpyrrolidone, methyl-1-methyl-5-oxopyrrolidine-3-carboxylate (MMOC), Delta-valerolactone, gamma butyrolactone, methyl 5-(dimethylamino)-2-methyl- 5-oxopentanoate (RhodiasolvOPolarclean), caprolactam, phenethyl acetate, methyl phenylacetate, benzyl benzoate, phenyl benzoate, methyl benzoate, and propyl benzoate.

[0230] 9. The process of any one of embodiments 1 to 8, wherein the one or more solvent(s) of the first solvent system is / are selected from the group consisting of propylenecarbonate, N- butylpyrrolidone, t-butylpyrrolidone, methyl-1-methyl-5-oxopyrrolidine-3-carboxylate (MMOC), methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate (RhodiasolvOPolarclean), phenethyl acetate, and GVL.

[0231] 10. The process of any one of embodiments 1 to 9, wherein the one or more solvent(s) of the first solvent system is / are selected from the group consisting of propylenecarbonate, N- butylpyrrolidone, t-butylpyrrolidone, methyl-1-methyl-5-oxopyrrolidine-3-carboxylate (MMOC), methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate (RhodiasolvOPolarclean), and phenethyl acetate.

[0232] 11 . The process of any one of embodiments 1 to 10, wherein the one or more solvent(s) of the first solvent system is / are selected from the group consisting of gamma valerolactone (GVL), N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone dimethyl sulfoxide (DMSO), dihydrolevoglucosenon (Cyrene) and mixtures of two or more thereof, or from the group consisting of N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone dimethyl sulfoxide (DMSO), dihydrolevoglucosenon (Cyrene), mixtures of two or more thereof.

[0233] 12. The process of any one of embodiments 1 to 11 , wherein the one or more solvent(s) of the first solvent system is / are selected from the group consisting of GVL, NBP, propylenecarbonate, acetophenone, DMSO, Cyrene and mixtures of two or more thereof, or from the group consisting of NBP, propylenecarbonate, acetophenone, DMSO, Cyrene and mixtures of two or more thereof.

[0234] 13. The process of any one of embodiments 1 to 12, wherein the one or more solvent(s) of the first solvent system is / are selected from the group consisting of GVL, NBP, propylenecarbonate, acetophenone, DMSO and mixtures of two or more thereof, or from the group consisting of NBP, propylenecarbonate, acetophenone, DMSO and mixtures of two or more thereof. The process of any one of embodiments 1 to 13, wherein the one or more solvent(s) of the first solvent system is / are selected from the group consisting of GVL, NBP, propylenecarbonate, acetophenone and mixtures of two or more thereof, or from the group consisting of NBP, propylenecarbonate, acetophenone and mixtures of two or three thereof. The process of any one of embodiments 1 to 14, wherein the one or more solvent(s) of the first solvent system comprise at least N-butylpyrrolidone (NBP), preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are NBP, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is NBP; or wherein the one or more solvent(s) of the first solvent system comprise at least propylenecarbonate, preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are propylenecarbonate, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is propylenecarbonate; or wherein the one or more solvent(s) of the first solvent system comprise at least acetophenone, preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are acetophenone, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is acetophenone; or wherein the one or more solvent(s) of the first solvent system comprise at least dimethyl suolfoxide (DMSO), preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are DMSO, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is DMSO; or wherein the one or more solvent(s) of the first solvent system comprise at least dihy- drolevoglucosenon (Gyrene), preferably at least 90 weight-% of the one or more solvents), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are Gyrene, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is Gyrene.

[0235] 16. The process of any one of embodiments 1 to 15, wherein ethyl benzoate and butyl benzoate are excluded as solvent(s) of the first solvent system.

[0236] 17. The process of any one of embodiments 1 to 16, wherein the first solvent system comprises GVL, wherein preferably at least 90 weight-%, more preferably at least 95 weight- %, more preferably at least 98 weight-%, more preferably in the range of from 99 to

[0237] 100 weight-%, based on the total weight of the solvent system being 100 weight-%, of the solvent system of the solvent system consist of GVL, more preferably the first solvent system is GVL.

[0238] 18. The process of any one of embodiments 1 to 17, wherein the re-obtained polyalkylene terephthalate based polymer of (c) has a number average molecular weight Mn, which is greater or at least equal to the Mn of the polyalkylene terephthalate based polymer comprised in the polymeric material provided in (a).

[0239] 19. The process of any one of embodiments 1 to 18, wherein the re-obtained polyalkylene terephthalate based polymer of (c) has a dispersity Mw / Mn (Mass average molecular weight Mw divided by number average molecular weight Mn) in the range of from 70 to 95%, preferably in the range of from 75 to 90 % of the dispersity Mw / Mn of the polyalkylene terephthalate based polymer comprised in the polymeric material provided in (a) (100%).

[0240] 20. The process of any one of embodiments 1 to 19, wherein at least 50 weight-%, preferably at least 60 weight-%, more preferably at least 70 weight-%, more preferably at least

[0241] 80 weight-%, more preferably at least 90 weight-%, more preferably at least 95 weight-%, more preferably at least 98 weight-% of the polymeric material comprising polyalkylene terephthalate based polymer are polyalkylene terephthalate based polymer, based on the total weight of the polymeric material comprising polyalkylene terephthalate based polymer being 100 weight-%.

[0242] 21 . The process of any one of embodiments 1 to 20, wherein the polymeric material comprising polyalkylene terephthalate based polymer further comprises at least one polymer different from polyalkylene terephthalate based polymer and optionally at least one colorant, wherein the at least one polymer different from polyalkylene terephthalate based polymer is preferably selected from the group consisting of polypropylene (PP), polyethylene (PE), polyamide (PA), natural polymer such as cotton, viscose and linen. The process of any one of embodiments 1 to 21 , wherein (b), if at least one insoluble polymer is present in the colored polymeric material comprising polyalkylene terephthalate based polymer provided in (a), preferably comprises:

[0243] (b.1) contacting the colored polymeric material with a first solvent system at a temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the first solvent in the solvent system, which has the lowest boiling point, thereby obtaining a first solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer; and a residue comprising at least one insoluble polymer selected from PP, PE, PA, natural polymer, viscose and linen;

[0244] (b.2) optionally separation of the solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer from the residue, thereby obtaining an insoluble polymer-free solvent system enriched in dissolved polyalkylene terephthalate based polymer and a residue comprising at least one insoluble polymer selected from PP, PE, PA, natural polymer, viscose and linen, wherein the separation is preferably done by heated filtration. The process of embodiment 22, wherein at least 40 weight-%, more preferably at least 50 weight-%, more preferably at least 60 weight-%, more preferably at least 70 weight-%, more preferably at least 80 weight-%, more preferably at least 90 weight-% of the polymeric material comprising polyalkylene terephthalate based polymer are the polyalkylene terephthalate based polymer, and at the outmost 60 weight-%, more preferably at the outmost 50 weight-%, more preferably at the outmost 40 weight-%, more preferably at the outmost 30 weight-%, more preferably at the outmost 20 weight-%, more preferably at the outmost 10 weight-% of the polymeric material comprising polyalkylene terephthalate based polymer are at least one polymer different from polyalkylene terephthalate based polymer and optionally at least one colorant, each based on the total weight of the polymeric material comprising polyalkylene terephthalate based polymer being 100 weight-%. The process of any one of embodiments 1 to 23, wherein the polyalkylene terephthalate based polymer consists of either oxyethylen units or oxybutylen units and oxyterephthaloyl units, wherein in case of oxyethylen units, in the range of from 0 to 5 mol-% of the oxyterephthaloyl units are replaced by oxyisophthaloyl units and / or in the range of from 0 to 49 mol-% of the oxyethylen units are replaced by oxymethylene cyclohexylene methylene units; wherein more preferably, the polyalkylene terephthalate based polymer is selected from the group consisting of PET (polyethylene terephthalate), , PETI (poly(ethylene ter- ephthalate-co-isophthalate)), PBT (polybutylene terephthalate), and mixtures of two or three of these polymers; wherein more preferably the polyalkylene terephthalate based polymer comprises or is PET. The process of any one of embodiments 1 to 24, wherein polymeric material comprising polyalkylene terephthalate based polymer and first solvent system are contacted in a mass-based ratio solvent system: polymeric material in the range of from 1 :1 to 100:1 , preferably in the range of from 1 :1 to 50:1 , more preferably in the range of from 1 :1 to 20:1 , more preferably in the range of from 1 :1 to 10:1. The process of any one of embodiments 1 to 25, wherein (b) and (c), preferably (a), (b) and (c) are done at a pressure in the range of from 800 to 200,000 hPa. The process of any one of embodiments 1 to 26, wherein (c) comprises:

[0245] (c.1) optionally after heated filtration, cooling the first solvent system obtained in (b), which is enriched in dissolved polyalkylene terephthalate based polymer compared to the first solvent system provided in (a) to a temperature below 160°C, preferably below 150°C, more preferably below 140°C, more preferably below 120°C;

[0246] (c.2) obtaining a precipitated polyalkylene terephthalate based polymer and a first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer. The process of embodiment 27, wherein cooling in (c.1) is done without addition of antisolvents. The process of any one of embodiments 1 to 28 comprising

[0247] (d) separating the precipitated polyalkylene terephthalate based polymer obtained in (c) or (c.2) from the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer, thereby obtaining a precipitated polyalkylene terephthalate based polymer and the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer. The process of any one of embodiments 1 to 29 comprising

[0248] (e) optionally washing the precipitated polyalkylene terephthalate based polymer obtained in (d);

[0249] (f) drying the precipitated polyalkylene terephthalate based polymer obtained in (d) or the washed precipitated polyalkylene terephthalate based polymer obtained in (e). The process of any one of embodiments 1 to 28 comprising: (a) providing the colored polymeric material comprising polyalkylene terephthalate based polymer and providing a first and a second solvent system;

[0250] (b) contacting the colored polymeric material with a first solvent system at a temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the first solvent in the solvent system, which has the lowest boiling point, thereby obtaining a first solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer;

[0251] (c) separating polyalkylene terephthalate based polymer from the first solvent system obtained in (b), thereby re-obtaining polyalkylene terephthalate based polymer comprising

[0252] (c.1) optionally after heated filtration, cooling the first solvent system obtained in (b) which is enriched in dissolved polyalkylene terephthalate based polymer compared to the first solvent system provided in (a) to a temperature below 160°C, preferably below 150°C, more preferably below 140°C, more preferably below 120°C;

[0253] (c.2) obtaining a precipitated polyalkylene terephthalate based polymer and a first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer;

[0254] (i’.1) separating the precipitated polyalkylene terephthalate based polymer obtained in (c.2) from the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer, thereby obtaining a precipitated polyalkylene terephthalate based polymer and the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer;

[0255] (i’.2) contacting the precipitated polyalkylene terephthalate based polymer of (i’.1) with a second solvent system at a temperature Ti, which is < 170 °C, thereby obtaining a second solvent system, which is enriched in colorant compared to the second solvent system provided in (a), and a polyalkylene terephthalate based polymer, which is depleted in colorant compared to the colored polymeric material provided in (a). The process of any one of embodiments 1 to 31 , wherein the second solvent system comprises one or more solvent(s), wherein

[0256] (s2.1a) the solvent system has Hansen solubility parameters with respect to

[0257] - energy from dispersion forces between molecules (5DSS),

[0258] - energy from dipolar intermolecular force between molecules (5PSS) and

[0259] - energy from hydrogen bonds between molecules (5HSS), which fulfill equitation 1

[0260] (8.8)2> 4(6Dss-20)2+ (6PSS-11.8)2+ (5Hss-4.5)2 [equitation 1];

[0261] (s2.2a) each solvent of the solvent system has a boiling point at 1013 hPa of at least 150 °C; and,

[0262] (s2.3a) solvents having a functional group selected from the group consisting of hydroxyl (OH), amino (NH2), carboxyl (COOH), and thiol (SH) are excluded. The process of any one of embodiments 1 to 32, wherein the one or more solvent(s) of the second solvent system is / are selected from the group indicated in embodiment 5, preferably form the group indicated in embodiment 6, more preferably from the group indicated in embodiment 7, more preferably from the group indicated in embodiment 8, more preferably from the group indicated in embodiment 9, more preferably from the group indicated in embodiment 10, more preferably wherein the one or more solvent(s) of the second solvent system is / are selected from the group consisting of gamma valerolactone (GVL), N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone dimethyl sulfoxide (DMSO), dihydrolevoglucosenon (Gyrene), cyclohexanone and mixtures of two or more thereof, or from the group consisting of N-butylpyrrolidone (NBP), propylenecarbonate, acetophenone dimethyl sulfoxide (DMSO), dihydrolevoglucosenon (Gyrene), cyclohexanone mixtures of two or more thereof; or wherein the one or more solvent(s) of the second solvent system is / are selected from the group consisting of GVL, NBP, propylenecarbonate, acetophenone, DMSO, Gyrene and mixtures of two or more thereof, or from the group consisting of NBP, propylenecarbonate, acetophenone, DMSO, Gyrene and mixtures of two or more thereof; or wherein the one or more solvent(s) of the second solvent system is / are selected from the group consisting of GVL, NBP, propylenecarbonate, acetophenone, DMSO and mixtures of two or more thereof, or from the group consisting of NBP, propylenecarbonate, acetophenone, DMSO and mixtures of two or more thereof; or wherein the one or more solvent(s) of the second solvent system is / are selected from the group consisting of GVL, NBP, propylenecarbonate, acetophenone and mixtures of two or more thereof, or from the group consisting of NBP, propylenecarbonate, acetophenone and mixtures of two or three thereof. The process of any one of embodiments 1 to 33, wherein the one or more solvent(s) of the second solvent system comprise at least gamma valerolactone (GVL), preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvents) are GVL, based on a total weight of the one or more solvent(s) being 100 weight- %, more preferably the one solvent is GVL; or wherein the one or more solvent(s) of the second solvent system comprise at least N-bu- tylpyrrolidone (NBP), preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are NBP, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is NBP; or wherein the one or more solvent(s) of the second solvent system comprise at least propylenecarbonate, preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are propylenecarbonate, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is propylenecarbonate; or wherein the one or more solvent(s) of the second solvent system comprise at least acetophenone, preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are acetophenone, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is acetophenone; or wherein the one or more solvent(s) of the second solvent system comprise at least dimethyl suolfoxide (DMSO), preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are DMSO, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is DMSO; or wherein the one or more solvent(s) of the second solvent system comprise at least dihy- drolevoglucosenon (Gyrene), preferably at least 90 weight-% of the one or more solvents), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are Gyrene, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is Gyrene; or wherein the one or more solvent(s) of the second solvent system comprise at least cyclohexanone, preferably at least 90 weight-% of the one or more solvent(s), more preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, more preferably at least 99.5 weight-%, more preferably at least 99.9 weight-%, of the one or more solvent(s) are cyclohexanone, based on a total weight of the one or more solvent(s) being 100 weight-%, more preferably the one solvent is cyclohexanone. 35. The process of embodiment 1 or 34, wherein at least 90 weight-%, preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, of the second solvent system consist of two or more solvent(s), wherein the respective mixture fulfill(s) equitation 2 or equitation 1; and / or wherein at least 90 weight-%, preferably at least 95 weight-%, more preferably at least 98 weight-%, more preferably at least 99 weight-%, of the first solvent system consist of one solvent, which fulfills equitation 2 or equitation 1.

[0263] 36. The process of any one of embodiments 1 to 35, wherein ethyl benzoate and butyl benzoate are excluded as solvent(s) of the second solvent system.

[0264] 37. The process of any one of embodiments 1 to 36, wherein the second solvent system comprises in least 90 weight-%, preferably at least 95 weight-% the same solvent(s) in the same amounts as the first solvent system, more preferably first solvent system and second solvent system are the same.

[0265] 38. The process of any one of embodiments 1 to 37, wherein the colorant is selected from the group consisting of dye and optical brightener and mixtures of dye and optical brightener.

[0266] 39. The process of any one of embodiments 1 to 38, wherein depleted in colorant regarding the polyalkylene terephthalate based polymer obtained means that the L*a*b* values of the polyalkylene terephthalate based polymer which is depleted in colorant compared to the polymeric material provided in (a), change in that: the absolute value of a* changes, preferably by at least 0.2; and / or, preferably and, the absolute value of b* changes, preferably by at least 0.2; and / or, preferably and, the L* value increases, preferably by at least 4, each compared to the L*a*b* values of the colored polymeric material provided in (a), wherein L*a*b* values are determined according to DIN 5033 and DIN EN ISO 11664-1.6.

[0267] 40. The process of any one of embodiments 1 to 39, comprising

[0268] (ii) separating the polyalkylene terephthalate based polymer, which is depleted in colorant from the second solvent system, which is enriched in colorant of (i).

[0269] 41. The process of embodiment 40, comprising

[0270] (iii) washing the separated polyalkylene terephthalate based polymer of (ii) with a washing solvent, thereby obtaining a washed polyalkylene terephthalate based polymer, which is depleted in colorant compared to the polymeric material provided in (a). The process of embodiment 40 or 41 , comprising

[0271] (iv) drying the separated polyalkylene terephthalate based polymer of (ii) and / or the washed polyalkylene terephthalate based polymer obtained in (iii). The process of any one of embodiments 1 to 42, wherein the re-obtained polyalkylene terephthalate based polymer of any one of steps (i), (ii), (iii) or (iv) has a number average molecular weight Mn, which is greater or at least equal to the Mn of the polyalkylene terephthalate based polymer comprised in the polymeric material provided in (a). The process of any one of embodiments 1 to 43, wherein the re-obtained polyalkylene terephthalate based polymer of any one of steps (i), (ii), (iii) or (iv) has a dispersity Mw / Mn (Mass average molecular weight Mw divided by number average molecular weight Mn) in the range of from 70 to 95 %, preferably in the range of from 75 to 90 % of the dispersity Mw / Mn of the polyalkylene terephthalate based polymer comprised in the polymeric material provided in (a) (100%). Polyalkylene terephthalate based polymer, which is depleted in colorant, obtained or obtainable from the process of any one of embodiments 1 to 434, preferably obtained or obtainable from any one of steps (i), (ii), (iii) or (iv). Use of the polyalkylene terephthalate based polymer, which is depleted in colorant of embodiment 45 for textile applications, fiber applications, packaging applications or plastic applications, preferably for the production of food packaging, beverage packaging, clothing and foot wear. The use of embodiment 46 for: a part of a car; preferably cylinder head cover, engine cover, housing for charge air cooler, charge air cooler flap, intake pipe, intake manifold, connector, gear wheel, fan wheel, cooling water box, housing, housing part for heat exchanger, coolant cooler, charge air cooler, thermostat, water pump, radiator, fastening part, part of battery system for electromobility, dashboard, steering column switch, seat, headrest, center console, transmission component, door module, A, B, C or D car pillar cover, spoiler, door handle, exterior mirror, windscreen wiper, windscreen wiper protection housing, decorative grill, cover strip, roof rail, window frame, sunroof frame, antenna panel, headlight and taillight, engine cover, cylinder head cover, intake manifold, airbag, cushion, or coating; a cloth; preferably shirt, trousers, pullover, boot, shoe, shoe sole, tight or jacket; an electrical part; preferably electrical or electronic passive or active component, circuit board, printed circuit board, housing component, foil, line, switch, plug, socket, distributor, relay, resistor, capacitor, inductor, bobbin, lamp, diode, LED, transistor, connector, regulator, integrated circuit (IC), processor, controller, memory, sensor, microswitch, microbutton, semiconductor, reflector housing for light-emitting diodes (LED), fastener for electrical or electronic component, spacer, bolt, strip, slide-in guide, screw, nut, film hinge, snap hook (snap-in), or spring tongue; a consumer, agricultural product or pharmaceutical product; preferably tennis string, climbing rope, bristle, brush, artificial grass, 3D printing filament, grass trimmer, zipper, hook and loop fastener, paper machine clothing, extrusion coating, fishing line, fishing net, offshore line and rope, vial, syringe, ampoule, bottle, sliding element, spindle nut, chain conveyor, plain bearing, roller, wheel, gear, roller, ring gear, screw and spring dampers, hose, pipeline, cable sheathing, socket, switch, cable tie, fan wheel, carpet, box or bottle for cosmetics, mattress, cushion, insulation, detergent, dishwasher tabs or powder, shampoo, body wash, shower gel, soap, fertilizer, fungicide, or pesticide; a packaging for the food industry; preferably mono- or multi-layer blown film, cast film (mono- or multi-layer), biaxially stretched film, or laminating film; or a part of a construction; preferably a rotor blade, insulating material, frame, housing, wall, coating, or separating wall. A method for preparing a textile or a packaging comprising

[0272] (A) providing polyalkylene terephthalate based polymer which is depleted in colorant, preferably polyalkylene terephthalate based polymer of embodiment 47;

[0273] (B) preparing a textile or a packaging from the polymeric material provided in (A). The method of embodiment 48, wherein in (B) a part of a car; preferably cylinder head cover, engine cover, housing for charge air cooler, charge air cooler flap, intake pipe, intake manifold, connector, gear wheel, fan wheel, cooling water box, housing, housing part for heat exchanger, coolant cooler, charge air cooler, thermostat, water pump, radiator, fastening part, part of battery system for electromobility, dashboard, steering column switch, seat, headrest, center console, transmission component, door module, A, B, C or D car pillar cover, spoiler, door handle, exterior mirror, windscreen wiper, windscreen wiper protection housing, decorative grill, cover strip, roof rail, window frame, sunroof frame, antenna panel, headlight and taillight, engine cover, cylinder head cover, intake manifold, airbag, cushion, or coating; a cloth; preferably shirt, trousers, pullover, boot, shoe, shoe sole, tight or jacket; an electrical part; preferably electrical or electronic passive or active component, circuit board, printed circuit board, housing component, foil, line, switch, plug, socket, distributor, relay, resistor, capacitor, inductor, bobbin, lamp, diode, LED, transistor, connector, regulator, integrated circuit (IC), processor, controller, memory, sensor, microswitch, microbutton, semiconductor, reflector housing for light-emitting diodes (LED), fastener for electrical or electronic component, spacer, bolt, strip, slide-in guide, screw, nut, film hinge, snap hook (snap-in), or spring tongue; a consumer, agricultural product or pharmaceutical product; preferably tennis string, climbing rope, bristle, brush, artificial grass, 3D printing filament, grass trimmer, zipper, hook and loop fastener, paper machine clothing, extrusion coating, fishing line, fishing net, offshore line and rope, vial, syringe, ampoule, bottle, sliding element, spindle nut, chain conveyor, plain bearing, roller, wheel, gear, roller, ring gear, screw and spring dampers, hose, pipeline, cable sheathing, socket, switch, cable tie, fan wheel, carpet, box or bottle for cosmetics, mattress, cushion, insulation, detergent, dishwasher tabs or powder, shampoo, body wash, shower gel, soap, fertilizer, fungicide, or pesticide; a packaging for the food industry; preferably mono- or multi-layer blown film, cast film (mono- or multi-layer), biaxially stretched film, or laminating film; or a part of a construction; preferably a rotor blade, insulating material, frame, housing, wall, coating, or separating wall, is prepared. Process, preferably according to any one of embodiments 1 to 44, comprising the further step: converting the re-obtained polyalkylene terephthalate based polymer obtained or obtainable by the process according to any one of embodiments 1 to 44 to obtain a polymer product. Process, preferably according to any one of embodiments 1 to 44, comprising the further step: converting the residue comprising at least one insoluble polymer selected from PP, PE, PA, natural polymer, viscose and linen obtainable by or obtained by the process according to the first aspect, preferably obtained or obtainable from step (b.2), to obtain one or more monomer, polymer or polymer product. Process according to embodiment 50, wherein the monomer is a di- or polyol; preferably butandiol; aldehyde; preferably formaldehyde; di- or polyisocyanate; preferably methylene diphenyl diisocyanate (MDI), polymeric methylene diphenyl diisocyanate (pMDI), toluene diisocyanate (TDI), hexamethylenediisocyanate (HDI) or isophoronediisocyanate (IPDI); amide; preferably caprolactam; alkene; preferably styrene, ethene and norbornene; alkyne, (di)ester; preferably methyl methacrylate; mono or diacid; preferably adipic acid or terephthalic acid; diamine; preferably hexamethylenediamine, nonanediamine; or sulfones; preferably 4,4'-dichlorodiphenyl sulfone. Process according to embodiment 50 or 51 , wherein the polymer is and / or the polymer product comprises polyamide (PA); preferably PA 6 or PA 66; polyisocyanate polyaddition product; preferably polyurethane (Pll), thermoplastic polyurethane (TPU), polyurea or polyisocyanurate (PIR); low- density polyethylene (LDPE), high-density polyethylene (HDPE), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyvinyl acetate (PVA), polystyrene (PS), poly acrylonitrile butadiene styrene (ABS), poly styrene acrylonitrile (SAN), poly acrylate styrene acrylonitrile (ASA), polytetrafluoroethylene (PTFE), poly(methyl acrylate) (PMA), poly(methyl methacrylate) (PMMA), polybutadiene (BR, PBD), poly(cis-1 ,4-isoprene), poly(trans-1 ,4-isoprene), polyoxymethylene (POM), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polybutylene adipate coterephthalate (PBAT), polyester (PES), polyether sulfone (PESLI), polyhydroxyalkanoate (PHA), poly-3-hydroxybutyrate (P3HB), poly-4-hydroxybutyrate (P4HB), polyhydroxyvalerate (PHV), polyhydroxyhexanoate (PHH), polyhydroxyoctanoate (PHO), polylactic acid (PLA), polysulfone (PSU), polyphenylene sulfone (PPSLI), polycarbonate (PC), polyether ether ketone (PEEK), poly(p-phenylene oxide) (PPO), poly(p-phenylene ether) (PPE); or copolymer or mixture thereof. Process according to any one of embodiments 50 to 52, wherein the polymer and / or the polymer product is / are or is / are a part of: a part of a car; preferably cylinder head cover, engine cover, housing for charge air cooler, charge air cooler flap, intake pipe, intake manifold, connector, gear wheel, fan wheel, cooling water box, housing, housing part for heat exchanger, coolant cooler, charge air cooler, thermostat, water pump, radiator, fastening part, part of battery system for electromobility, dashboard, steering column switch, seat, headrest, center console, transmission component, door module, A, B, C or D car pillar cover, spoiler, door handle, exterior mirror, windscreen wiper, windscreen wiper protection housing, decorative grill, cover strip, roof rail, window frame, sunroof frame, antenna panel, headlight and taillight, engine cover, cylinder head cover, intake manifold, airbag, cushion, or coating; a cloth; preferably shirt, trousers, pullover, boot, shoe, shoe sole, tight or jacket; an electrical part; preferably electrical or electronic passive or active component, circuit board, printed circuit board, housing component, foil, line, switch, plug, socket, distributor, relay, resistor, capacitor, inductor, bobbin, lamp, diode, LED, transistor, connector, regulator, integrated circuit (IC), processor, controller, memory, sensor, microswitch, microbutton, semiconductor, reflector housing for light-emitting diodes (LED), fastener for electrical or electronic component, spacer, bolt, strip, slide-in guide, screw, nut, film hinge, snap hook (snap-in), or spring tongue; a consumer, agricultural product or pharmaceutical product; preferably tennis string, climbing rope, bristle, brush, artificial grass, 3D printing filament, grass trimmer, zipper, hook and loop fastener, paper machine clothing, extrusion coating, fishing line, fishing net, offshore line and rope, vial, syringe, ampoule, bottle, sliding element, spindle nut, chain conveyor, plain bearing, roller, wheel, gear, roller, ring gear, screw and spring dampers, hose, pipeline, cable sheathing, socket, switch, cable tie, fan wheel, carpet, box or bottle for cosmetics, mattress, cushion, insulation, detergent, dishwasher tabs or powder, shampoo, body wash, shower gel, soap, fertilizer, fungicide, or pesticide; a packaging for the food industry; preferably mono- or multi-layer blown film, cast film (mono- or multi-layer), biaxially stretched film, or laminating film; or a part of a construction; preferably a rotor blade, insulating material, frame, housing, wall, coating, or separating wall.

[0274] 54. Process according to any one of embodiments 50 to 53, wherein the content of the at least one insoluble polymer selected from PP, PE, PA, natural polymer, viscose and linen in the polymer and / or polymer product is 1 weight-% or more, preferably 2 weight-% or more, more preferably 5 weight-% or more, more preferably 15 weight-% or more, more preferably 30 weight-% or more, more preferably 40 weight-% or more, more preferably 60 weight-% or more, more preferably 80 weight-% or more, more preferably 90 weight-% or more, more preferably 95 weight-% or more; and / or wherein the content of the at least one insoluble polymer selected from PP, PE, PA, natural polymer, viscose and linen in the polymer and / or polymer product is 100 weight-% or less, preferably 95 weight-% or less, more preferably 90 weight-% or less, more preferably 50 weight-% or less, more preferably 25 weight-% or less, more preferably 10 weight-% or less; and preferably wherein the content is determined based on identity preservation and / or segregation and / or mass balance and / or book and claim chain of custody models, preferably based on mass balance, preferably the International Sustainability and Carbon Certification (ISCC) standard.

[0275] The present invention is further illustrated by the following reference examples, comparative examples, and examples.

[0276] Examples

[0277] Methods for analytics:

[0278] GPC (Gel-Permeation Chromatography):

[0279] Sample preparation:

[0280] 7.5 mg sample was dissolved in 5 ml eluent (hexafluorisopropanol + 0.05 weight-% trifluoro potassium acetate) over night. All sample solutions were filtered by a Millipore Millex FG (0.2 pm) filtered prior to injection. Sealed sample vials were placed into the auto sampler.

[0281] Experimental conditions:

[0282] An Agilent 1100 HPLC system, consisting of an isocratic pump, vacuum degasser, auto sampler and a column oven (40°C) was used. Furthermore, the Agilent system contained as detectors a Differential Refractive Index (DRI) and a variable Ultra Violet (UVW) Detector. Data acquisition and data processing of conventionally SEC data were done by WinGPC Unichrom, of PSS (Polymer Standard Services). A combination of a PL-HFIP guard (7.5 x 50 mm) column and 2 PL- HFIP Gel columns (7.5 x 300 mm, 9p) of Agilent were put in series. As an eluent, hexafluorisopropanol + 0.05 weight-% trifluoro potassium acetate was used as a flow rate of 1 ml / min. Of each sample solution 50pl was injected. The calibration was obtained by narrow molar mass distributed PMMA standards (Polymer Standard Services) having a molar mass range of M= 800 till M = 2.200.000 g / mol. Molar masses outside this range were extrapolated.

[0283] CIE-LAB:

[0284] L*a*b* values were determined in that the samples were measured using an integrating sphere and UV / VIS-remission spectra (with a wavelength area of 400-700 nm) were obtained. The data of these spectra were analyzed by the software OptLab-SPX using 2° standard observer and the standard light type C. The OptLab-SPX software calculates the L*a*b*-values based on DIN 5033 and DIN EN ISO 11664-1.6 from the years 2007-2014.

[0285] Chemicals

[0286] Reference Example 1 : General Procedure for dissolution of PET

[0287] Colored polymeric PET material (in any colour) was cut / shredded into pieces and placed in a reaction vessel (e.g. flask, tube, reaction vessel). The solvent was added (in mass-based ratio solvent : polymeric material 100:1 to 1 :1, preferred 10:1-1:1) and the mixture was heated by use of a suitable heating system (e.g. oil bath, heating blocks, mini-plant vessels) to the maximum of a) the respective boiling point of the solvent, or b) to 210 °C, both under an inert gas atmosphere, wherein PET was fully dissolved upon visual inspection. After 1-30 min the mixture was allowed to cool-down while the PET precipitated. The precipitate was filtrated and washed with a small amount of the individual solvent. For an easy removal of said solvent and a faster drying process of the re-obtained PET powder, small amounts of acetone can be used in a second washing step. The thus obtained solid was dried (for example in a vacuum compartment dryer).

[0288] Reference Example 2: General Procedure for discoloration of recycled PET

[0289] 10 g of recycled PET obtained from Reference Example 1 was placed in a reaction vessel (e.g. flask, tube, reaction vessel). The solvent was added (in mass-based ratio solvent : polymeric material 100:1 to 1 :1, preferred 10:1-1 :1) and the mixture was heated by use of a suitable heating system (e.g. oil bath, heating blocks, mini-plant vessels) to a temperature in the range of from 60 to 160 °C. After 0.5-8 h the mixture was filtered, whereby the solvent enriched in colorant and discolored polymeric material was obtained and the discolored polymeric material was washed with a small amount of the respective solvent. For an easy removal of said solvent and a faster drying process of the colour-depleted polymeric material pieces, small amounts of acetone can be used in a second washing step. The thus obtained colour-depleted polymeric material were dried (for example in a vacuum compartment dryer).

[0290] Reference Example 3: General Procedure for combined dissolution and discoloration of recycled PET Colored polymeric PET material (in any colour) was cut / shredded into pieces and placed in a reaction vessel (e.g. flask, tube, reaction vessel). The solvent was added (in mass-based ratio solvent : polymeric material 100:1 to 1 :1, preferred 10:1-1:1) and the mixture was heated by use of a suitable heating system (e.g. oil bath, heating blocks, mini-plant vessels) to the maximum of a) the respective boiling point of the solvent, or b) to 210 °C, both under an inert gas atmosphere, wherein PET was fully dissolved upon visual inspection. After 1-30 min the mixture was allowed to cool-down while the PET precipitated. The precipitate was filtrated and washed at a temperature in the range of from 60 to 160 °C with solvent, whereby the solvent enriched in colorant and discolored polymeric material (on the filter) were obtained. The colour-depleted polymeric material was washed with the respective solvent, preferably on / within the same device that was used for filtration. For an easy removal of said solvent and a faster drying process of the colour-depleted polymeric material pieces, small amounts of acetone can be used in a second washing step. The thus obtained colour-depleted polymeric material were dried (for example in a vacuum compartment dryer).

[0291] Examples 1 to 6: Dissolution and discoloration

[0292] Shredded flakes of colored polymeric PET material were dissolved following the procedure of Reference Example 1 and the recycled PET obtained from said procedure was then discolored following the procedure of Reference Example 2. After the final drying step of Reference Example 2 (recycled and re-obtained colour-depleted PET solid), the L*a*b* values were determined. The results are summarized in Table 1 below.

[0293] Table 1

[0294] Overview material and results of Examples 1 to 6.

[0295] For the green PET textile of Example 2, molecular weights (Mn, Mw) and dispersity were determined based on GPC before and after the treatment. The same was done for the black PET textile of Examples 4, 5 and 6. The results are shown below in Table 2.

[0296] Table 2

[0297] Molecular weights and dispersity of green textile before and after treatment (GPC)

[0298] It was found that dissolution of a colored polymeric material comprising PET with a solvent system fulfilling (s1 .1), (s1.2) and (s1.3), followed by a discoloration with a with a solvent system fulfilling at least (s2.1) and (s2.2) resulted in an efficient colorant removal. Furthermore, the process allowed to re-obtain a non-degraded PET - the Mn of the re-obtained PET was always about equal to the Mn of the PET comprised in the material initially provided. The re-obtained PET had a dispersity Mw / Mn (Mass average molecular weight Mw divided by number average molecular weight Mn) in the range of from 70 to 95%, preferably in the range of from 75 to 90 % of the dispersity Mw / Mn of the PET comprised in the colored polymeric material initially provided (100%).

[0299] Description of Figure

[0300] Fig. 1 shows a schematic overview comparing the process variants wherein in (A) steps (d), (e) and step (i) are carried out separately and in (B) steps (i’.1) and (i’.2) are carried out within the same device. “Polyalkylene terephthalate based polymer” is abbreviated as PATbP

[0301] Cited Literature

[0302] WO 2016 / 12755 A 1

[0303] Wenjun Chen, Yuechao Yang, Xue Lan, Baolong Zhang, Xiaogang Zhang and Tiancheng Mu in Green Chem., 2021 , 23, 4065

[0304] WO 2022 / 221832 A 1 “Dyes and Pigments” Metin Agikyildiz, Kubra Gunes, Ahmet Gurses Springer, 2016 (ISBN: 10 : 3319338900)

[0305] Industrial Organic Pigments - Klaus Hunger, Thomas Heber, Martin II. Schmidt, Friedrich Reisinger, Stefan Wanne Wiley- VCH, 4thedition, 2018 (ISBN: 978-3-527-32608-2)

[0306] Chemistry and Technology of Natural and Synthetic Dyes and Pigments - Ashis Kumar Samanta, Nasser Awwad, IntechOpen, 2020 (ISBN: 9781789859980, 9781789859973, 9781839687587)

[0307] Encyclopedia of Color, Dyes, Pigments - Volume 1 , Gerhard Pfaff, de Gruyter, 2021 (ISBN: 311058588X)

[0308] Heinrich Zollinger: Color Chemistry: Syntheses, Properties, and Applications of Organic Dyes and Pigments. 3rdedition. WILEY- CH Verlag, Weinheim 2003 (ISBN: 3-906390-23- 3)

[0309] Klaus Hunger (Ed.): Industrial Dyes: Chemistry, Properties, Applications. WILEY-VCH Verlag, Weinheim 2003 (ISBN: 3-662-01950-7)

[0310] Hermann Rath: Lehrbuch der Textilchemie. einschl. der textilchemischen Technologie. 2nd edition. Springer-Verlag, Berlin, Heidelberg 1963 (ISBN: 978-3-662-00065-6)

[0311] Wilfried Kratzert, Rasmus Peichert: Farbstoffe. Quelle & Meyer, Heidelberg 1981 (ISBN: 3-494-01021-8)

[0312] Ullmann’s Encyclopedia of industrial chemistry, Wiley-VCH, 2000, sections “dyes and pigments” and “dyes, general survey” (ISBN: 9783527303854)

[0313] “Industrial Organic Chemistry”, 3. volume, Wiley-VCH, 1997, ISBN: 978-3-527-28838-0,

[0314] „Kunststoffhandbuch“, Carl Hanser Verlag; vol. 6, „Polyamide“, 1. edition, 1966,

[0315] Kunststoffhandbuch", Carl Hanser Verlag; vol. 7, ..Polyurethane", 3. edition, 1993,

[0316] Kunststoffhandbuch", Carl Hanser Verlag; vol. 8, “Polyester”, 2. edition 1973;

[0317] “Industrial Organic Chemistry”, 3. volume, Wiley-VCH, 1997, ISBN: 978-3-527-28838-0,

[0318] “Injection Molding Reference Guide, 4th edition, CreateSpace Independent Publishing Platform, 2011 , ISBN: 978-1466407824,

[0319] EP 0989146 A1

[0320] EP 1460094 A1

[0321] WO 2006034800 A1

[0322] EP 1529792 A1

[0323] WO 2006042674 A1

[0324] EP 0364854 A2

[0325] US 5506275 A EP 0897402 A1

[0326] WO 2015082316 A1

[0327] WO 2021021855 A1

[0328] WO 2021126938 A 1 - WO 2021021902 A1

[0329] WO 2021092311 A1

[0330] WO 2008155271 A1

[0331] WO 2013139827 A1

Claims

Claims1 . A process for recovery of a polyalkylene terephthalate based polymer from a colored polymeric material, the process comprising:(a) providing the colored polymeric material comprising polyalkylene terephthalate based polymer and providing a first and a second solvent system;(b) contacting the colored polymeric material with a first solvent system at a temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the first solvent in the solvent system, which has the lowest boiling point, thereby obtaining a first solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer;(c) separating polyalkylene terephthalate based polymer from the solvent system obtained in (b), thereby re-obtaining polyalkylene terephthalate based polymer; wherein the first solvent system comprises gamma valerolactone (GVL),;(i) contacting the re-obtained polyalkylene terephthalate based polymer of (c) with a second solvent system at a temperature Ti, which is < 170 °C, thereby obtaining a second solvent system, which is enriched in colorant compared to the solvent system provided in (a), and a polyalkylene terephthalate based polymer, which is depleted in colorant compared to the colored polymeric material provided in (a); wherein the second solvent system comprises gamma valerolactone (GVL).

2. The process of claim 1 , wherein contacting in (b) is done at a temperature in the range of from 160 °C to the temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the solvent in the solvent system, which has the lowest boiling point.

3. The process of claim 1 or 2, wherein at least 90 weight-%, more preferably at least95 weight-%, more preferably at least 98 weight-%, more preferably in the range of from99 to 100 weight-%, based on the total weight of the first solvent system being100 weight-%, consist of GVL, more preferably the first solvent system is GVL.

4. The process of any one of claims 1 to 3, wherein the polymeric material comprising polyalkylene terephthalate based polymer further comprises at least one polymer different from polyalkylene terephthalate based polymer and optionally at least one colorant, wherein the at least one polymer different from polyalkylene terephthalate based polymer is preferably selected from the group consisting of polypropylene (PP), polyethylene (PE), polyamide (PA), natural polymer such as cotton, viscose and linen.

5. The process of any one of claims 1 to 4, wherein (b), if at least one insoluble polymer is present in the colored polymeric material comprising polyalkylene terephthalate based polymer provided in (a), preferably comprises:(b.1) contacting the colored polymeric material with a first solvent system at a temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the first solvent in the solvent system, which has the lowest boiling point, thereby obtaining a first solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer; and a residue comprising at least one insoluble polymer selected from PP, PE, PA, natural polymer, viscose and linen;(b.2) optionally separation of the solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer from the residue, thereby obtaining an insoluble polymer-free solvent system enriched in dissolved polyalkylene terephthalate based polymer and a residue comprising at least one insoluble polymer selected from PP, PE, PA, natural polymer, viscose and linen, wherein the separation is preferably done by heated filtration; and / or, preferably and, wherein (c) comprises:(c.1) optionally after heated filtration, cooling the first solvent system obtained in (b), which is enriched in dissolved polyalkylene terephthalate based polymer compared to the first solvent system provided in (a) to a temperature below 160°C, preferably below 150°C, more preferably below 140°C, more preferably below 120°C;(c.2) obtaining a precipitated polyalkylene terephthalate based polymer and a first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer; and / or(d) separating the precipitated polyalkylene terephthalate based polymer obtained in (c) or (c.2) from the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer, thereby obtaining a precipitated polyalkylene terephthalate based polymer and the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer; and / or(e) optionally washing the precipitated polyalkylene terephthalate based polymer obtained in (d);(f) drying the precipitated polyalkylene terephthalate based polymer obtained in (d) or the washed precipitated polyalkylene terephthalate based polymer obtained in (e).

6. The process of any one of claims 1 to 4 comprising:(a) providing the colored polymeric material comprising polyalkylene terephthalate based polymer and providing a first and a second solvent system;(b) contacting the colored polymeric material with a first solvent system at a temperature T, which is at least 1 K, preferably at least 7K, below the boiling temperature of the first solvent in the solvent system, which has the lowest boiling point, thereby obtaining a first solvent system, which is enriched in dissolved polyalkylene terephthalate based polymer;(c) separating polyalkylene terephthalate based polymer from the first solvent system obtained in (b), thereby re-obtaining polyalkylene terephthalate based polymer comprising(c.1) optionally after heated filtration, cooling the first solvent system obtained in (b) which is enriched in dissolved polyalkylene terephthalate based polymer compared to the first solvent system provided in (a) to a temperature below 160°C, preferably below 150°C, more preferably below 140°C, more preferably below 120°C;(c.2) obtaining a precipitated polyalkylene terephthalate based polymer and a first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer;(i’.1) separating the precipitated polyalkylene terephthalate based polymer obtained in (c.2) from the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer, thereby obtaining a precipitated polyalkylene terephthalate based polymer and the first solvent system, which is depleted in dissolved polyalkylene terephthalate based polymer;(i’.2) contacting the precipitated polyalkylene terephthalate based polymer of (i’.1) with a second solvent system at a temperature Ti, which is < 170 °C, thereby obtaining a second solvent system, which is enriched in colorant compared to the second solvent system provided in (a), and a polyalkylene terephthalate based polymer, which is depleted in colorant compared to the colored polymeric material provided in (a).

7. The process of any one of claims 1 to 6, comprising(ii) separating the polyalkylene terephthalate based polymer, which is depleted in colorant from the second solvent system, which is enriched in colorant of (i); and preferably(iii) washing the separated polyalkylene terephthalate based polymer of (ii) with a washing solvent, thereby obtaining a washed polyalkylene terephthalate based polymer, which is depleted in colorant compared to the polymeric material provided in (a); and preferably(iv) drying the separated polyalkylene terephthalate based polymer of (ii) and / or the washed polyalkylene terephthalate based polymer obtained in (iii).

8. The process of any one of claims 1 to 7, wherein the re-obtained polyalkylene terephthalate based polymer of any one of steps (i), (ii), (iii) or (iv) has a number average molecular weight Mn, which is greater or at least equal to the Mn of the polyalkylene terephthalate based polymer comprised in the polymeric material provided in (a); and / or wherein the re-obtained polyalkylene terephthalate based polymer of any one of steps (i), (ii), (iii) or (iv) has a dispersity Mw / Mn (Mass average molecular weight Mw divided by number average molecular weight Mn) in the range of from 70 to 95 %, preferably in the range of from 75 to 90 % of the dispersity Mw / Mn of the polyalkylene terephthalate based polymer comprised in the polymeric material provided in (a).

9. The process of any one of claims 1 to 8, wherein the polyalkylene terephthalate based polymer consists of either oxyethylen units or oxybutylen units and oxyterephthaloyl units, wherein in case of oxyethylen units, in the range of from 0 to 5 mol-% of the oxyterephthaloyl units are replaced by oxyisophthaloyl units and / or in the range of from 0 to 49 mol- % of the oxyethylen units are replaced by oxymethylene cyclohexylene methylene units; wherein more preferably, the polyalkylene terephthalate based polymer is selected from the group consisting of PET (polyethylene terephthalate), PETI (poly(ethylene tereph- thalate-co-isophthalate)), PBT (polybutylene terephthalate), and mixtures of two or three of these polymers; wherein more preferably the polyalkylene terephthalate based polymer comprises or is PET.

10. Polyalkylene terephthalate based polymer, which is depleted in colorant, obtained or obtainable from the process of any one of claims 1 to 9, preferably obtained or obtainable from any one of steps (i), (ii), (iii) or (iv).

11. Use of the polyalkylene terephthalate based polymer, which is depleted in colorant of claim 10 for textile applications, fiber applications, packaging applications or plastic applications, preferably for the production of food packaging, beverage packaging, clothing and foot wear.

12. A method for preparing a textile or a packaging comprising(A) providing polyalkylene terephthalate based polymer which is depleted in colorant, preferably polyalkylene terephthalate based polymer of claim 10;(B) preparing a textile or a packaging from the polymeric material provided in (A).

13. Process according to any one of claims 1 to 9, comprising the further step:converting the residue comprising at least one insoluble polymer selected from PP, PE, PA, natural polymer, viscose and linen obtainable by or obtained by the process according to the first aspect, preferably obtained or obtainable from step (b.2), to obtain one or more monomer, polymer or polymer product; and / or converting the re-obtained polyalkylene terephthalate based polymer obtained by the process according to any one of claims 1 to 9 to obtain a polymer product.

14. Process according to claim 13, wherein the monomer is a di- or polyol; preferably butandiol; aldehyde; preferably formaldehyde; di- or polyisocyanate; preferably methylene diphenyl diisocyanate (MDI), polymeric methylene diphenyl diisocyanate (pMDI), toluene diisocyanate (TDI), hexamethylenediisocyanate (HDI) or isophoronediisocyanate (IPDI); amide; preferably caprolactam; alkene; preferably styrene, ethene and norbornene; alkyne, (di)ester; preferably methyl methacrylate; mono or diacid; preferably adipic acid or terephthalic acid; diamine; preferably hexamethylenediamine, nonanediamine; or sulfones; preferably 4,4'-dichlorodiphenyl sulfone; and / or wherein the polymer is and / or the polymer product comprises polyamide (PA); preferably PA 6 or PA 66; polyisocyanate polyaddition product; preferably polyurethane (Pll), thermoplastic polyurethane (TPU), polyurea or polyisocyanurate (PIR); low-density polyethylene (LDPE), high-density polyethylene (HDPE), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyvinyl acetate (PVA), polystyrene (PS), poly acrylonitrile butadiene styrene (ABS), poly styrene acrylonitrile (SAN), poly acrylate styrene acrylonitrile (ASA), polytetrafluoroethylene (PTFE), poly(methyl acrylate) (PMA), poly(methyl methacrylate) (PMMA), polybutadiene (BR, PBD), poly(cis-1 ,4-isoprene), poly(trans-1 ,4-iso- prene), polyoxymethylene (POM), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polybutylene adipate coterephthalate (PBAT), polyester (PES), polyether sulfone (PESLI), polyhydroxyalkanoate (PHA), poly-3-hydroxybutyrate (P3HB), poly-4-hy- droxybutyrate (P4HB), polyhydroxyvalerate (PHV), polyhydroxyhexanoate (PHH), polyhydroxyoctanoate (PHO), polylactic acid (PLA), polysulfone (PSU), polyphenylene sulfone (PPSLI), polycarbonate (PC), polyether ether ketone (PEEK), poly(p-phenylene oxide) (PPO), poly(p-phenylene ether) (PPE); or copolymer or mixture thereof; and / or wherein the polymer and / or the polymer product is / are or is / are a part of: a part of a car; preferably cylinder head cover, engine cover, housing for charge air cooler, charge air cooler flap, intake pipe, intake manifold, connector, gear wheel, fan wheel, cooling water box, housing, housing part for heat exchanger, coolant cooler, charge air cooler, thermostat, water pump, radiator, fastening part, part ofbattery system for electromobility, dashboard, steering column switch, seat, headrest, center console, transmission component, door module, A, B, C or D car pillar cover, spoiler, door handle, exterior mirror, windscreen wiper, windscreen wiper protection housing, decorative grill, cover strip, roof rail, window frame, sunroof frame, antenna panel, headlight and taillight, engine cover, cylinder head cover, intake manifold, airbag, cushion, or coating; a cloth; preferably shirt, trousers, pullover, boot, shoe, shoe sole, tight or jacket; an electrical part; preferably electrical or electronic passive or active component, circuit board, printed circuit board, housing component, foil, line, switch, plug, socket, distributor, relay, resistor, capacitor, inductor, bobbin, lamp, diode, LED, transistor, connector, regulator, integrated circuit (IC), processor, controller, memory, sensor, microswitch, microbutton, semiconductor, reflector housing for light-emitting diodes (LED), fastener for electrical or electronic component, spacer, bolt, strip, slide-in guide, screw, nut, film hinge, snap hook (snap-in), or spring tongue; a consumer, agricultural product or pharmaceutical product; preferably tennis string, climbing rope, bristle, brush, artificial grass, 3D printing filament, grass trimmer, zipper, hook and loop fastener, paper machine clothing, extrusion coating, fishing line, fishing net, offshore line and rope, vial, syringe, ampoule, bottle, sliding element, spindle nut, chain conveyor, plain bearing, roller, wheel, gear, roller, ring gear, screw and spring dampers, hose, pipeline, cable sheathing, socket, switch, cable tie, fan wheel, carpet, box or bottle for cosmetics, mattress, cushion, insulation, detergent, dishwasher tabs or powder, shampoo, body wash, shower gel, soap, fertilizer, fungicide, or pesticide; a packaging for the food industry; preferably mono- or multi-layer blown film, cast film (mono- or multi-layer), biaxially stretched film, or laminating film; or a part of a construction; preferably a rotor blade, insulating material, frame, housing, wall, coating, or separating wall; and / or wherein the content of the at least one insoluble polymer selected from PP, PE, PA, natural polymer, viscose and linen in the polymer and / or polymer product is 1 weight-% or more, preferably 2 weight-% or more, more preferably 5 weight-% or more, more preferably 15 weight-% or more, more preferably 30 weight-% or more, more preferably 40 weight-% or more, more preferably 60 weight-% or more, more preferably 80 weight-% or more, more preferably 90 weight-% or more, more preferably 95 weight-% or more; and / or wherein the content of the at least one insoluble polymer selected from PP, PE, PA, natural polymer, viscose and linen in the polymer and / or polymer product is 100 weight-% or less, preferably 95 weight-% or less, more preferably 90 weight-% or less, more preferably50 weight-% or less, more preferably 25 weight-% or less, more preferably 10 weight- % or less; and preferably wherein the content is determined based on identity preservation and / or segregation and / or mass balance and / or book and claim chain of custody models, preferably based on mass balance, preferably the International Sustainability and Carbon Certification (ISCC) standard.

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