Method for recovering polyethylene terephthalate using specific color coordinates for oligomer treatment

Abstract

A process for producing a first intermediate product comprising the steps of: a. Providing a feedstock comprising a first polyester; b. Contacting the first polyester with a further organic compound, preferably in volume segment V3, to obtain a further initial mixture; c. Reducing the weight average molar mass of the first polyester, preferably in the volume segment V3, to obtain a first intermediate mixture comprising: i. The first intermediate product, ii. Another organic compound; d. Adjusting the b value of the Hunter Lab color coordinate of the first intermediate mixture, preferably in the volume segment V5; wherein the b value of the Hunter Lab color coordinates of the first intermediate mixture is adjusted such that b < = 0, more preferably b < =-1, and further preferably b < =-2.

Description

Field of the Invention

[0001] The present invention relates to a method for producing a first intermediate from a first polyester, for example, a method for producing polyethylene terephthalate (PET) oligomers from PET flakes. The present invention also relates to the first intermediate obtained by the above method. The present invention also relates to a method for producing another intermediate using the first intermediate, for example, producing a PET polymer using PET oligomers. The present invention also relates to another intermediate. The present invention also relates to a product comprising another intermediate, such as PET yarn.

[0002] Background

[0003] Polyethylene terephthalate (PET) is one of the most widely used and economically important thermoplastic polymers. PET is used, for example, in clothing fibers, food and beverage containers (such as bottles), and films.

[0004] Due to the widespread use of PET and its non - biodegradability, products containing PET have caused serious ecological problems. Therefore, methods for recycling PET are very important for reducing the amount of PET waste. One recycling method is to reduce PET to the chemical components used to produce PET and then polymerize the chemical components to obtain recycled PET. This is called chemical recycling. The disadvantages of the chemical recycling process include: the recycling process is usually very energy - consuming, not environmentally friendly, and has low yields. In particular, if PET is depolymerized into monomers, it requires a long depolymerization time and results in the generation of a large amount of degradation products that cannot be removed from the recycled PET. It is also usually necessary to mix chemically recycled PET with virgin PET to obtain a recycled PET product of sufficient quality.

[0005] For example, Bartolome et al. (2012), Recent Developments in the Chemical Recycling of PET, Material Recycling–Trends and Perspectives describes the chemical recycling of polyethylene terephthalate. EP3778744A1 discloses a method for recycling PET, including mixing virgin PET liquid material (virgin PET liquid material is defined as the chemical components required to produce virgin PET, i.e., PET not obtained using a recycling method) with recycled PET. CN109134244 A discloses a method for recycling PET that uses ethylene glycol and methanol to depolymerize PET. CN108395373 A discloses a method for recycling PET that uses ethylene glycol and propylene glycol.

[0006] Objective

[0007] An object of the present invention is to at least partially overcome at least one drawback encountered in the prior art.

[0008] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method can remove more impurities during the production of the first intermediate product. The sources of impurities include raw materials (for the method of producing the first intermediate product), which contain impurities such as sand and polyvinyl chloride.

[0009] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method can remove more alkali during the production of the first intermediate product. The presence of alkali may be due to, for example, the raw materials (for the method of producing the first intermediate product) having been alkali-washed.

[0010] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method can more effectively remove the adhesive adhered to the raw materials (for the method of producing the first intermediate product).

[0011] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the transportation rate of the raw materials through the production plant is increased. Here, the raw materials refer to the raw materials of the method for producing the first intermediate product, and the production plant refers to the plant for producing the first intermediate product.

[0012] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method reduces the occurrence of blockages, for example, blockages occurring in the production plant for producing the first intermediate product.

[0013] Another object of the present invention is to provide a method for producing a first intermediate product, which requires less energy.

[0014] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method has an increased yield.

[0015] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method has a reduced carbon footprint.

[0016] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the first intermediate product has an improved purity.

[0017] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method reduces the degradation of the first intermediate product.

[0018] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method results in an increase in the uptime of the plant performing the method for producing the first intermediate product.

[0019] Another object of the present invention is to provide a first intermediate that can be used in a method for producing another intermediate product.

[0020] Another object of the present invention is to provide a method for producing another intermediate product, wherein the method requires less energy.

[0021] Another object of the present invention is to provide a method for producing another intermediate product, wherein the method has a reduced carbon footprint.

[0022] Another object of the present invention is to provide a method for producing another intermediate product, wherein the method has an increased yield.

[0023] Another object of the present invention is to provide a method for producing another intermediate product, wherein the method has a reduced polymerization time.

[0024] Another object of the present invention is to provide a method for producing another intermediate product, wherein the other intermediate product has an improved color quality.

[0025] Another object of the present invention is to provide a method for producing another intermediate product, wherein the other intermediate product has an improved purity.

[0026] Another object of the present invention is to provide a method for producing another intermediate product, wherein the other intermediate product is obtained by using an increased amount of the first intermediate. For example, the other intermediate product is a PET polymer obtained by polymerizing PET oligomers and PET monomers (the first intermediate), wherein the PET oligomers and PET monomers are obtained by depolymerizing PET products; furthermore, the PET polymer is obtained by adding less than 1% of the original PET oligomers and esters that can be used to produce PET.

[0027] Another object of the present invention is to provide another intermediate product having an improved color quality.

[0028] Another object of the present invention is to provide another intermediate product having an improved purity.

[0029] Preferred Embodiments of the Invention

[0030] Any embodiment of the present invention contributes to at least partially achieving at least one of the above objects.

[0031] The first embodiment of the present invention is a method for producing a first intermediate, comprising the following steps

[0032] a. Providing a raw material containing a first polyester;

[0034] b. Contacting the first polyester with another organic compound, preferably in volume section V 3to obtain another initial mixture;

[0035] c. reducing the weight average molar mass of the first polyester, preferably in volume section V 3 to obtain a first intermediate mixture, wherein the first intermediate mixture comprises

[0036] i. a first intermediate product,

[0037] ii. another organic compound;

[0038] d. adjusting, preferably in volume cross-section V5, the b value of the Hunter Lab color coordinates of the first intermediate mixture; wherein,

[0039] wherein, adjusting the b value of the Hunter Lab color coordinates of the first intermediate mixture such that b ≤ 0, more preferably b ≤ -1, and even more preferably b ≤ -2.

[0040] In one aspect of the first embodiment, preferably, adjusting, preferably in volume section V 5 of, the Hunter Lab color coordinates of the first intermediate mixture such that b is in the range of -10 to -3, more preferably in the range of -9 to -4, and even more preferably in the range of -8 to -6. In one aspect of the first embodiment, preferably, the first intermediate mixture further comprises a first organic compound. In one aspect of the first embodiment, preferably, the another organic compound is in liquid form. In a preferred embodiment of the method for producing the first intermediate product, the density of the first polyester in the raw material is in the range of 1.25 g / cm 3 to 1.55 g / cm 3 more preferably in the range of 1.28 g / cm 3 to 1.50 g / cm 3 and even more preferably in the range of 1.31 g / cm 3 to 1.47 g / cm 3 This preferred embodiment is the second embodiment of the present invention, which preferably depends on the first embodiment of the present invention.

[0041] In one aspect of the second embodiment, examples of the first polyester are amorphous PET with a density in the range of 1.33 g / cm 3 to 1.39 g / cm 3 and single crystal PET with a density of 1.455 g / cm 3

[0042] In a preferred embodiment of the method for producing the first intermediate, the first polyester is selected from polyethylene terephthalate, polybutylene terephthalate, polylactic acid, polypropylene terephthalate, polyethylene naphthalate, polycarbonate, polyester carbonate, polyarylate, polyester resin (preferably unsaturated polyester resin), and combinations of two or more thereof. This preferred embodiment is the 3rd embodiment of the present invention, which preferably depends on any one of the 1st to 2nd embodiments of the present invention.

[0043] In one aspect of the 3rd embodiment, it is particularly preferred that the first polyester is polyethylene terephthalate.

[0044] In a preferred embodiment of the method for producing the first intermediate, the raw material comprises at least 65 wt-%, more preferably at least 85 wt-%, even more preferably at least 95 wt-%, and further preferably at least 99 wt-% of the first polyester, based on the total mass of the raw material. This preferred embodiment is the 4th embodiment of the present invention, which preferably depends on any one of the 1st to 3rd embodiments of the present invention.

[0045] In one aspect of the 4th embodiment, it is preferred that the first polyester is polyethylene terephthalate. In another aspect of the 4th embodiment, it is preferred that the raw material comprises less than 1 wt-%, more preferably less than 0.1 wt-%, and further preferably less than 0.01 wt-% of polyamide, based on the total mass of the raw material.

[0046] In a preferred embodiment of the method for producing the first intermediate, the bulk density of the raw material is in the range of 0.10 g / cm 3 to 0.75 g / cm 3 more preferably in the range of 0.15 g / cm 3 to 0.65 g / cm 3 even more preferably in the range of 0.18 g / cm 3 to 0.50 g / cm 3 further preferably in the range of 0.20 g / cm 3 to 0.40 g / cm 3 even further preferably in the range of 0.22 g / cm 3 to 0.37 g / cm 3 This preferred embodiment is the 5th embodiment of the present invention, which preferably depends on any one of the 1st to 4th embodiments of the present invention.

[0047] In a preferred embodiment of the method for producing the first intermediate, the raw material further comprises at least one impurity. This preferred embodiment is the 6th embodiment of the present invention, which preferably depends on any one of the 1st to 5th embodiments of the present invention.

[0048] In a preferred embodiment of the method for producing the first intermediate, at least one impurity in the raw material is in the range of 10 ppm wt to 10000 ppm wt, more preferably in the range of 20 ppm wt to 4000 ppm wt, even more preferably in the range of 30 ppm wt to 3000 ppm wt, and further preferably in the range of 40 ppm wt to 2500 ppm wt, where the mass is based on the total mass of the raw material. This preferred embodiment is the 7th embodiment of the present invention, which preferably depends on the 6th embodiment of the present invention.

[0049] In one aspect of the 7th embodiment, it is preferred to measure the ppm value of at least one impurity after the raw material has undergone a cleaning step. In another aspect of the 7th embodiment, it is preferred to measure the ppm value given for at least one impurity when the first polyester is provided in the form of a plurality of fragments.

[0050] In a preferred embodiment of the method for producing the first intermediate, the first polyester in the raw material is in the form of a plurality of fragments. This preferred embodiment is the 8th embodiment of the present invention, which preferably depends on any one of the 1st to 7th embodiments of the present invention.

[0051] In a preferred embodiment of the method for producing the first intermediate, the form of the fragments is selected from flakes, threads, fibers, granules, pieces, sheets, films, and combinations of two or more thereof. This preferred embodiment is the 9th embodiment of the present invention, which preferably depends on the 8th embodiment of the present invention.

[0052] In one aspect of the 9th embodiment, flakes are particularly preferred.

[0053] In a preferred embodiment of the method for producing the first intermediate, based on the total mass of the plurality of fragments in the raw material, at least 50 wt-%, more preferably at least 60 wt-%, even more preferably at least 70 wt-%, further preferably at least 80 wt-%, and even further preferably at least 85 wt-% of the fragments have at least one or all of the following characteristics:

[0054] a. The first dimension is in the range of 0.1 mm to 25.0 mm, more preferably in the range of 0.5 mm to 20.0 mm, even more preferably in the range of 1.0 mm to 15.0 mm, and further preferably in the range of 2.5 mm to 13 mm;

[0055] b. The thickness is in the range of 0.1 mm to 3.5 mm, more preferably in the range of 0.2 mm to 3.0 mm, and further preferably in the range of 0.3 mm to 2.7 mm.

[0056] This preferred embodiment is the 10th embodiment of the present invention, which preferably depends on any one of the 8th to 9th embodiments of the present invention.

[0057] Examples of the first dimension in the 10th embodiment are width and length. In one aspect of the 10th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b.

[0058] In a preferred embodiment of the method for producing the first intermediate product, based on the total mass of the plurality of fragments in the raw material, 30 wt-% or less, more preferably 27 wt-% or less, even more preferably 23 wt-% or less, and further preferably 20 wt-% or less of the fragments have a thickness equal to or greater than 1.0 mm. This preferred embodiment is the 11th embodiment of the present invention, which preferably depends on any one of the 8th to 10th embodiments of the present invention.

[0059] In an alternative aspect of the 11th embodiment, fragments in the range of 1 wt-% to 30 wt-%, optionally in the range of 2 wt-% to 27 wt-%, optionally in the range of 5 wt-% to 23 wt-%, or optionally in the range of 7 wt-% to 20 wt-% have a thickness equal to or greater than 1.0 mm. In one aspect of the 11th embodiment, preferably, the wt-% range applies to fragments having a thickness in the range of 1.0 mm to 4.0 mm, more preferably in the range of 1.0 mm to 3.5 mm, and further preferably in the range of 1.0 mm to 2.7 mm.

[0060] In a preferred embodiment of the method for producing the first intermediate product, the plurality of fragments are at least partially classified according to physical properties. This preferred embodiment is the 12th embodiment of the present invention, which preferably depends on any one of the 8th to 11th embodiments of the present invention.

[0061] In one aspect of the 12th embodiment, at least partial classification is preferably carried out according to at least one of the following properties of the fragments: mass, thickness, color, optical classification based on light absorption, electrical properties, aerodynamic properties, width, length, geometry (such as curvature), or a combination of two or more of them. In one aspect of the 12th embodiment, preferably, the classification is carried out before contacting the raw material with a first amount of a first organic compound in, preferably in volume section V 1 of, the first organic compound. In one aspect of the 12th embodiment, preferably, the physical property is not the density of the fragment.

[0062] In a preferred embodiment of the method for producing the first intermediate product, at least partial classification of the plurality of fragments is carried out using at least one or all of the following:

[0063] a. A sieve;

[0064] b. Gravity separator;

[0065] c. Device adapted and arranged for sedimentation;

[0066] d. Centrifuge.

[0067] This preferred embodiment is the 13th embodiment of the present invention, which preferably depends on the 12th embodiment of the present invention.

[0068] In one aspect of the 13th embodiment, all possible combinations of features a. to d. are preferred aspects of this embodiment. These combinations are, for example, a; b; c; d; a + b; a + c; a + d; b + c; b + d; c + d; a + b + c; a + b + d; a + c + d; b + c + d; a + b + c + d. In one aspect of the 13th embodiment, it is preferred to use a device that does not utilize the density of the first polyester for at least part of the above classification. In one aspect of the 13th embodiment, a gravity separator is particularly preferred. In this aspect, a gravity separator that does not require fluid for at least part of the classification is more preferred. Suitable gravity separators are available, for example, from Cimbria Heid GmbH (Austria).

[0069] In a preferred embodiment of the method for producing the first intermediate product, the first organic compound has at least one or all of the following properties:

[0070] a. Containing at least two hydroxyl groups, such as a diol having 2 hydroxyl groups, a triol having 3 hydroxyl groups;

[0071] b. The molar mass is at least 60 g / mol;

[0072] c. The boiling point is at least 192 °C, more preferably at least 195 °C.

[0073] This preferred embodiment is the 14th embodiment of the present invention, which preferably depends on any one of the 1st to 13th embodiments of the present invention.

[0074] Examples of the first organic compound include (mono)ethylene glycol, propylene glycol, and glycerol. In one aspect of the 14th embodiment, all possible combinations of features a. to c. are preferred aspects of this embodiment. These combinations are, for example, a; b; c; a + b; a + c; b + c; a + b + c. In one aspect of the 14th embodiment, it is particularly preferred that the first organic compound is (mono)ethylene glycol, and more preferably monoethylene glycol. In one aspect of the 14th embodiment, it is particularly preferred that the first organic compound is not propylene glycol.

[0075] In a preferred embodiment of the method for producing the first intermediate product, the method further comprises the step of contacting the raw material with a first amount of the first organic compound, preferably in volume section V1 to obtain a first initial mixture, wherein the first amount is in liquid form. This preferred embodiment is the 15th embodiment of the present invention, which preferably depends on any one of the 1st to 14th embodiments of the present invention.

[0076] In one aspect of the 15th embodiment, preferably, the raw material is contacted with the first amount of the first organic compound before contacting the first polyester with an additional amount of the first organic compound. In one aspect of the 15th embodiment, preferably, at least a portion of the first amount of the first organic compound is fed into volume section V before the raw material is contacted with the first amount of the first organic compound 1 . In this regard, it is preferred to feed into volume section V 1 the temperature of at least a portion of the first amount of the first organic compound is in the range of 100 °C to 160 °C, more preferably in the range of 115 °C to 145 °C. In one aspect of the 15th embodiment, preferably, the first polyester is fed into volume section V before the raw material is contacted with the first amount of the first organic compound 1 . In this regard, it is preferred to feed into volume section V 1 the temperature of the first polyester is in the range of 0 °C to 60 °C, more preferably in the range of 10 °C to 40 °C. In one aspect of the 15th embodiment, preferably, at least a portion of the first amount of the first organic compound and the raw material are fed into volume section V separately before the raw material is contacted with the first amount of the first organic compound 1 . For example, different inlets are used to feed this portion of the first amount and the raw material into volume section V 1 .

[0077] In a preferred embodiment of the method for producing the first intermediate, the mass ratio of the raw material (more preferably the first polyester) to the first amount of the first organic compound (preferably in volume section V 1 ) is in the range of 0.02 to 3, more preferably in the range of 0.04 to 2.8, even more preferably in the range of 0.06 to 2.6, further preferably in the range of 0.08 to 2.4, and still further preferably in the range of 0.09 to 2.2. This preferred embodiment is the 16th embodiment of the present invention, which preferably depends on the 15th embodiment of the present invention.

[0078] In one aspect of the 16th embodiment, more preferably, the mass ratio of the raw material (more preferably the first polyester) to the first organic compound in volume section V 1 is in the range of 0.02 to 1.3, more preferably in the range of 0.04 to 0.5, even more preferably in the range of 0.06 to 0.28, further preferably in the range of 0.08 to 0.22, and still further preferably in the range of 0.09 to 0.16. In one aspect of the 16th embodiment, more preferably, the temperature in volume section V 1 is in the range of 55 °C to 80℃ within a range. In one aspect of the 16th embodiment, even more preferably, the temperature in volume segment V 1 is lower than 79 ℃ . In one aspect of the 16th embodiment, more preferably, the temperature in volume segment V 1 is within the range of 65 ℃ to 77 ℃ . In a preferred embodiment of the method for producing the first intermediate, the temperature of the first initial mixture in volume segment V 1 is within the range of 50 °C to 90 °C, more preferably within the range of 55 °C to 85 °C, even more preferably within the range of 55 °C to 80 °C, further preferably within the range of 60 °C to 80 °C, and even further preferably within the range of 65 °C to 77 °C. This preferred embodiment is the 17th embodiment of the present invention, which preferably depends on any one of the 15th to 16th embodiments of the present invention.

[0079] In one aspect of the 17th embodiment, it is particularly preferred that the temperature of the first initial mixture is lower than the glass transition temperature of the first polyester. In one aspect of the 17th embodiment, preferably, the temperature difference between the first polyester in volume segment V 1 and the temperature of the first organic compound in volume segment V 1 is less than 4%, more preferably less than 2%, and further preferably less than 1%.

[0080] In a preferred embodiment of the method for producing the first intermediate, the intrinsic viscosity of the first polyester in volume segment V 1 is within the range of 0.50 dL / g to 1.00 dL / g, more preferably within the range of 0.60 dL / g to 0.95 dL / g, even more preferably within the range of 0.70 dL / g to 0.90 dL / g, and further preferably within the range of 0.76 dL / g to 0.84 dL / g. This preferred embodiment is the 18th embodiment of the present invention, which preferably depends on any one of the 15th to 17th embodiments of the present invention.

[0081] In a preferred embodiment of the method for producing the first intermediate, at least one or all of the following apply to the first polyester in volume segment V 1 :

[0082] a. The change in the intrinsic viscosity of the first polyester is less than 15%, more preferably less than 10%, even more preferably less than 7%, further preferably less than 5%, and even further preferably less than 3%;

[0083] b. The change in the weight-average molar mass of the first polyester is less than 20%, more preferably less than 15%, even more preferably less than 10%, further preferably less than 7%, and even further preferably less than 5%.

[0084] This preferred embodiment is the 19th embodiment of the present invention, which preferably depends on any one of the 15th to 18th embodiments of the present invention.

[0085] In one aspect of the 19th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b.

[0086] In a preferred embodiment of the method for producing the first intermediate, at least one of the following or all apply:

[0087] a. Before contacting with the first amount of the first organic compound, the weight average molar mass of the first polyester is in the range of 50,000 Da to 73,000 Da, more preferably in the range of 54,000 Da to 68,000 Da, and further preferably in the range of 57,000 Da to 65,000 Da;

[0088] b. The weight average molar mass of the first polyester leaving volume section V 1 is in the range of 40,000 Da to 76,000 Da, more preferably in the range of 44,000 Da to 74,000 Da, even more preferably in the range of 48,000 Da to 72,000 Da, and further preferably in the range of 50,000 Da to 70,000 Da.

[0089] This preferred embodiment is the 20th embodiment of the present invention, which preferably depends on any one of the 15th to 19th embodiments of the present invention.

[0090] In one aspect of the 20th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b. In one aspect of the 20th embodiment, it is preferred that the weight average molar mass of the first polyester leaving volume section V 1 is in the range of 51,000 Da to 55,000 Da.

[0091] In a preferred embodiment of the method for producing the first intermediate, the relative ratio of the number of particles per unit area of at least one impurity in the raw material to the number of particles per unit area of at least one impurity at the outlet of volume section V 1 is equal to or greater than 15, more preferably equal to or greater than 20, even more preferably equal to or greater than 25, further preferably equal to or greater than 30, and even further preferably equal to or greater than 35. This preferred embodiment is the 21st embodiment of the present invention, which preferably depends on any one of the 15th to 20th embodiments of the present invention.

[0092] In one aspect of the 21st embodiment, it is preferred that the relative ratio of the number of particles per unit area of at least one impurity in the raw material to the number of particles per unit area of at least one impurity at the outlet of volume section V1 The relative proportion of the number of particles per unit area of at least one impurity at the outlet is equal to or less than 1000, more preferably equal to or less than 500, and even more preferably equal to or less than 250.

[0093] In a preferred embodiment of the method for producing the first intermediate, the residence time of the first polyester in volume section V 1 is from 5 minutes to 45 minutes, more preferably from 8 minutes to 40 minutes, and further preferably from 10 minutes to 30 minutes. This preferred embodiment is the 22nd embodiment of the present invention, which preferably depends on any one of the 15th to 21st embodiments of the present invention.

[0094] In a preferred embodiment of the method for producing the first intermediate, the pressure in volume section V 1 is in the range of 75 kPa to 130 kPa, more preferably in the range of 90 kPa to 115 kPa, further preferably in the range of 95 kPa to 107 kPa, and even further preferably in the range of 98 kPa to 103 kPa. This preferred embodiment is the 23rd embodiment of the present invention, which preferably depends on any one of the 15th to 22nd embodiments of the present invention.

[0095] In one aspect of the 23rd embodiment, the pressure in volume section V 1 is preferably atmospheric pressure.

[0096] In a preferred embodiment of the method for producing the first intermediate, the method further comprises preferably stirring the first initial mixture in volume section V 1 This preferred embodiment is the 24th embodiment of the present invention, which preferably depends on any one of the 15th to 23rd embodiments of the present invention.

[0097] In one aspect of the 24th embodiment, it is preferred to stir the first initial mixture using a mechanical device designed and arranged for stirring, a non - mechanical device designed and arranged for stirring, or a combination thereof. In this aspect, it is further preferred that the mechanical device, non - mechanical device, or both are designed and arranged to suspend particles in a liquid, for example, to suspend multiple fragments of a raw material in a first organic compound. For example, the suspension of particles can be achieved by using a mechanical stirring device with a rotational speed per minute higher than a minimum value. In one aspect of the 24th embodiment, it is preferred to stir the first initial mixture such that impurities can float on the surface of the first initial mixture. This can be achieved, for example, by using a stirring device with a rotational speed per minute lower than a maximum value.

[0098] In a preferred embodiment of the method for producing the first intermediate, the method further comprises at least partially from preferably in volume section V 1The step of removing at least one impurity from the first initial mixture therein. This preferred embodiment is the 25th embodiment of the present invention, which preferably depends on any one of the 15th to 24th embodiments of the present invention.

[0099] In one aspect of the 25th embodiment, it is preferred that at least one impurity is present in the raw material. In one aspect of the 25th embodiment, it is preferred to use a floatable separation device to at least partially remove at least one impurity. In another aspect of the 25th embodiment, it is preferred to use skimming, filtration, or a combination thereof to at least partially remove at least one impurity.

[0100] In a preferred embodiment of the method for producing the first intermediate product, the method further includes preferably transporting the first polyester from volume section V 1 to volume section V 2 . This preferred embodiment is the 26th embodiment of the present invention, which preferably depends on any one of the 1st to 25th embodiments of the present invention.

[0101] In one aspect of the 26th embodiment, it is preferred to transport the first polyester to volume section V 1 after the raw material has contacted a first amount of the first organic compound in volume section V 2 . In another aspect of the 26th embodiment, it is preferred to transport at least a portion of the first organic compound in volume section V 1 together with the first polyester to volume section V 2 . In another aspect of the 26th embodiment, it is preferred that at least a portion of the first organic compound in volume section V 2 is transported (e.g., flows) from volume section V 2 to volume section V 1 . In one aspect of the 26th embodiment, it is preferred to transport the first polyester to volume section V 2 before the first polyester contacts another organic compound. In one aspect of the 26th embodiment, it is preferred that the transport direction of the first polyester through volume section V 2 is at least partially opposite to the direction of gravity, more preferably opposite to the direction of gravity. In one aspect of the 26th embodiment, it is preferred that volume section V 2 is at least partially vertically arranged, more preferably vertically arranged. At least partially vertically arranged should preferably be understood as the longest dimension (e.g., length) of volume section V 2 not being parallel to the ground. For example, if volume section V 2 is vertically arranged, then the length of volume section V 2 is perpendicular to the ground.

[0102] In a preferred embodiment of the method for producing the first intermediate product, volume section V 2 is at least partially filled with the first organic compound, where

[0103] i. The height of the level of the first organic compound in volume segment V from the floor is H 1 and 1

[0104] ii. The height of the level of the first organic compound in volume segment V from the floor is H 2 and 2

[0105] and

[0106] wherein H 1 < H 2 .

[0107] This preferred embodiment is the 27th embodiment of the present invention, which preferably depends on any one of the 15th to 26th embodiments of the present invention.

[0108] In one aspect of the 27th embodiment, it is preferred that at least a portion of the first organic compound in volume segment V 2 is conveyed from volume segment V 1 . In another aspect of the 27th embodiment, it is preferred that at least a portion of the first organic compound in volume segment V 2 is added through at least one inlet of volume segment V 2 , such as another type of inlet and yet another type of inlet. In this aspect, it is preferred that at least 50 wt-%, more preferably at least 60 wt-%, and even more preferably at least 70 wt-% of the first organic compound in volume segment V 2 is due to the addition of the first organic compound through at least one inlet of volume segment V 2 . This wt-% is based on the total mass of the first organic compound in volume segment V 2 . "Additional amount of the first organic compound" is an example of a portion of the first organic compound added through at least one inlet. In one aspect of the 27th embodiment, it is preferred to convey the first polyester from volume segment V 1 to volume segment V 2 through a siphon.

[0109] In a preferred embodiment of the method for producing the first intermediate product, the difference H 2 - H 1 is at least 1 cm, more preferably at least 10 cm, even more preferably at least 30 cm, and even further preferably at least 60 cm. This preferred embodiment is the 28th embodiment of the present invention, which preferably depends on the 27th embodiment of the present invention.

[0110] In one aspect of the 28th embodiment, it is preferred that the difference H 2 - H 1 ​​Less than 250 cm, more preferably less than 180 cm, even more preferably less than 160 cm, and further preferably less than 140 cm.

[0111] In a preferred embodiment of the method for producing the first intermediate, before entering volume section V 2 the first polyester is conveyed in a further direction, where the further direction is at least partially opposite to the direction of gravity. This preferred embodiment is the 29th embodiment of the present invention, which preferably depends on any one of the 26th to 28th embodiments of the present invention.

[0112] In one aspect of the 29th embodiment, it is preferred that at least a part of the first organic compound is conveyed in a direction opposite to the further direction. For example, the first polyester and a part of the first organic compound are conveyed in opposite directions.

[0113] In a preferred embodiment of the method for producing the first intermediate, the angle between the further direction and the horizontal plane is in the range of 12° to 45°, more preferably in the range of 17° to 40°, even more preferably in the range of 20° to 35°, and further preferably in the range of 24° to 32°. This preferred embodiment is the 30th embodiment of the present invention, which preferably depends on the 29th embodiment of the present invention.

[0114] In one aspect of the 30th embodiment, an example of the horizontal plane is the floor, such as the floor of a recycling factory. In one aspect of the 30th embodiment, it is preferred that the horizontal plane is perpendicular to the direction of gravity.

[0115] In a preferred embodiment of the method for producing the first intermediate, the method further includes the step of bringing the first polyester into contact with an additional amount of the first organic compound, preferably in volume section V 2 therein. This preferred embodiment is the 31st embodiment of the present invention, which preferably depends on any one of the 1st to 30th embodiments of the present invention.

[0116] In one aspect of the 31st embodiment, it is preferred that the first polyester is brought into contact with an additional amount of the first organic compound before being brought into contact with another organic compound.

[0117] In a preferred embodiment of the method for producing the first intermediate, the method further includes the step of increasing the temperature of the first polyester, preferably in volume section V 2 therein. This preferred embodiment is the 32nd embodiment of the present invention, which preferably depends on any one of the 1st to 31st embodiments of the present invention.

[0118] In one aspect of the 32nd embodiment, it is preferred to increase the temperature by bringing the first polyester into contact with an additional amount of the first organic compound. In one aspect of the 32nd embodiment, it is preferred to increase the temperature before the first polyester is brought into contact with another organic compound.

[0119] In a preferred embodiment of the method for producing the first intermediate, the temperature in volume section V 2 is in the range of 50°C to 220°C, more preferably in the range of 60°C to 210°C, even more preferably in the range of 65°C to 205°C, and still further preferably in the range of 68°C to 200°C. This preferred embodiment is the 33rd embodiment of the present invention, which preferably depends on any one of the 26th to 32nd embodiments of the present invention.

[0120] In one aspect of the 33rd embodiment, preferably the temperature in volume section V 2 is the temperature of a mixture comprising the first polyester and the first organic compound.

[0121] In a preferred embodiment of the method for producing the first intermediate, volume section V 2 comprises a first region and another region, where at least one or all of the following apply:

[0122] a. The relative ratio of the temperature of the first region to the temperature of the another region is in the range of 0.2 to 1.0, more preferably in the range of 0.3 to 0.9, and still further preferably in the range of 0.4 to 0.8;

[0123] b. The relative ratio of the mass ratio of the first polyester to the first organic compound in the first region to the mass ratio of the first polyester to the first organic compound in the another region is in the range of 0.01 to 0.90, more preferably in the range of 0.02 to 0.60, even more preferably in the range of 0.03 to 0.30, and still further preferably in the range of 0.04 to 0.15.

[0124] This preferred embodiment is the 34th embodiment of the present invention, which preferably depends on any one of the 26th to 33rd embodiments of the present invention.

[0125] In one aspect of the 34th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are for example a; b; a + b.

[0126] In a preferred embodiment of the method for producing the first intermediate, volume section V 2 comprises a first region and another region, where at least one or all of the following apply:

[0127] a. The temperature of the first region is in the range of 50°C to 220°C, preferably in the range of 50°C to 190°C, more preferably in the range of 60°C to 180°C, even more preferably in the range of 65°C to 170°C, still further preferably in the range of 68°C to 160°C, and even still further preferably in the range of 68°C to 150°C;

[0128] b. The temperature of another region is from 120 °C to 220 °C, more preferably from 130 °C to 210 °C, even more preferably from 135 °C to 205 °C, and still further preferably from 138 °C to 200 °C;

[0129] c. The mass ratio of the first polyester to the first organic compound in the first region is from 0.1 to 0.9, more preferably from 0.2 to 0.8, even more preferably from 0.3 to 0.6, and still further preferably from 0.4 to 0.5;

[0130] d. The mass ratio of the first polyester to the first organic compound in another region is in the range of 1 to 20, more preferably in the range of 2 to 16, even more preferably in the range of 3 to 12, and still further preferably in the range of 5 to 10.

[0131] This preferred embodiment is the 35th embodiment of the present invention, which preferably depends on any one of the 26th to 34th embodiments of the present invention.

[0132] In one aspect of the 35th embodiment, all possible combinations of features a. to d. are preferred aspects of this embodiment. These combinations are, for example, a; b; c; d; a + b; a + c; a + d; b + c; b + d; c + d; a + b + c; a + b + d; a + c + d; b + c + d; a + b + c + d. In one aspect of the 35th embodiment, it is preferred that the temperature of the first region increases from the first end of the first region to the other end of the first region. For example, the temperature increases from 70 °C measured at the first end of the first region to 145 °C measured at the other end of the first region. In this aspect, it is preferred that the first end of the first region is downstream of the other end of the first region. For example, the first end of the first region is near the entrance of volume section V 2 through which the first polyester enters volume section V 2 . In another aspect of the 35th embodiment, it is preferred that the temperature of another region increases from the first end to the other end of another region. For example, the temperature increases from 140 °C measured at the first end of another region to 200 °C measured at the other end of another region. In this regard, it is preferred that the first end of another region is downstream of the other end of another region. For example, the other end of another region is near the exit of volume section V 2 through which the first polyester exits volume section V 2 . For example, from volume section V 2The inlet is moved to the outlet, and the ends of the zones are arranged in the following order: the first end of the first zone, the other end of the first zone, the first end of the other zone, and the other end of the other zone. In another aspect of the 35th embodiment, preferably, the other end of the first zone forms the first end of the other zone. In one aspect of the 35th embodiment, in feature a., particularly preferably, the temperature in the first zone is in the range of 50°C to 190°C, more preferably in the range of 60°C to 180°C, even more preferably in the range of 65°C to 170°C, further preferably in the range of 68°C to 160°C, and even further preferably in the range of 68°C to 150°C. In one aspect of the 35th embodiment, in feature a., preferably, the temperature in the first zone is in the range of 60°C to 210°C, more preferably in the range of 60°C to 200°C, further preferably in the range of 65°C to 197°C, and even further preferably in the range of 67°C to 196°C. In one aspect of the 35th embodiment, in feature a., particularly preferably, the temperature in the first zone is in the range of 50°C to 196°C, more preferably in the range of 55°C to 196°C, even more preferably in the range of 60°C to 196°C, further preferably in the range of 65°C to 196°C, and even further preferably in the range of 68°C to 196°C. In one aspect of the 35th embodiment, in feature a., preferably the temperature of the first zone is lower than the boiling point of the first organic compound. In one aspect of the 35th embodiment, in feature b., preferably the temperature of the other zone is in the range of 160°C to 220°C, more preferably in the range of 170°C to 210°C, even more preferably in the range of 180°C to 200°C, further preferably in the range of 185°C to 196°C, and even further preferably in the range of 190°C to 196°C. In one aspect of the 35th embodiment, in feature b., preferably the temperature of the other zone is lower than the boiling point of the first organic compound.

[0133] In a preferred embodiment of the method for producing the first intermediate, at least one or all of the following apply:

[0134] a. A first portion of an additional amount of the first organic compound in contact with the first polyester is in gaseous form, such as vapor;

[0135] b. Another portion of an additional amount of the first organic compound in contact with the first polyester is in liquid form.

[0136] This preferred embodiment is the 36th embodiment of the present invention, which preferably depends on any one of the 31st to 35th embodiments of the present invention.

[0137] In the 36th embodiment, the first part and the other part are measured in wt-%, based on the total mass of the additional amount of the first organic compound in contact with the first polyester. In one aspect of the 36th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b. In the 36th embodiment, the "part" (e.g., the first part, the other part) should preferably be understood to include a value of 100 wt-%. For example, in one aspect of the 36th embodiment, where only feature a. applies, the first part will be 100 wt-%. In the 36th embodiment, the first part should preferably be understood to include the first organic compound that was initially in gaseous form but has condensed before coming into contact with the first polyester. In one aspect of the 36th embodiment, for feature a., preferably, the temperature of the first part of the additional amount of the first organic compound is higher than the boiling point of the first organic compound. In one aspect of the 36th embodiment, for feature a., preferably, the temperature of the first part of the additional amount of the first organic compound is in the range of 200 °C to 240 °C, more preferably in the range of 210 °C to 230 °C. In one aspect of the 36th embodiment, for feature b., preferably, the temperature of the other part of the additional amount of the first organic compound is lower than the boiling point of the first organic compound. In one aspect of the 36th embodiment, for feature b., preferably, the temperature of the other part of the additional amount of the first organic compound is in the range of 180 °C to 196 °C, more preferably in the range of 190 °C to 196 °C.

[0138] In a preferred embodiment of the method for producing the first intermediate product, the first part accounts for 50 wt-% to 90 wt-% of the additional amount of the first organic compound, more preferably 55 wt-% to 85 wt-%, even more preferably 60 wt-% to 80 wt-%, and further preferably 65 wt-% to 75 wt-%. This wt-% is based on the total mass of the additional amount of the first organic compound. This preferred embodiment is the 37th embodiment of the present invention, which preferably depends on the 36th embodiment of the present invention.

[0139] In the 37th embodiment, the sum of the wt-% of the first part and the wt-% of the other part is 100 wt-%. For example, if the first part accounts for 55 wt-% of the additional amount of the first organic compound, then the other part accounts for the remaining 45 wt-% of the additional amount of the first organic compound.

[0140] In a preferred embodiment of the method for producing the first intermediate product, the first polyester enters volume section V through at least one inlet of the first type 2 , where at least one or all of the following apply:

[0141] a. At least a portion (e.g., a first portion) of an additional amount of the first organic compound, preferably in gaseous form, enters the volume section V through at least one inlet of another type 2 , wherein at least one inlet of another type is adjusted and arranged such that the additional amount of the first organic compound entering through at least one inlet of another type passes through the volume section V 2 in a flow direction that is at least partially along the transport direction of the first polyester through the volume section V 2 ;

[0142] b. At least a portion (e.g., another portion) of an additional amount of the first organic compound, preferably in liquid form, enters the volume section V through at least one inlet of yet another type 2 , wherein at least one inlet of yet another type is adjusted and arranged such that the additional amount of the first organic compound entering through at least one inlet of yet another type passes through the volume section V 2 in a flow direction that is at least partially opposite to the transport direction of the first polyester through the volume section V 2 ;

[0143] This preferred embodiment is the 38th embodiment of the present invention, which preferably depends on any one of the 31st to 37th embodiments of the present invention

[0144] In one aspect of the 38th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b. In one aspect of the 38th embodiment, it is preferred that the transport direction of the first polyester through the volume section V 2 is parallel to the length of the volume section V 2 . In one aspect of the 38th embodiment, it is preferred that the transport direction of the first polyester through the volume section V 2 is at least partially opposite to the direction of gravity. In this aspect, it is more preferred that the transport direction is opposite to the direction of gravity. In one aspect of the 38th embodiment, it is preferred that the portion in feature a. is the first portion of the additional amount of the first organic compound. In one aspect of the 38th embodiment, it is preferred that the portion in feature b. is the other portion of the additional amount of the first organic compound

[0145] In a preferred embodiment of the method for producing the first intermediate product, at least one impurity is present in the volume section V 2 . This preferred embodiment is the 39th embodiment of the present invention, which preferably depends on any one of the 26th to 38th embodiments of the present invention

[0146] In the 39th embodiment, an example of at least one impurity is an impurity present in the raw material, and this impurity is transported from the volume section V 1 to the volume section V 2 .

[0147] In a preferred embodiment of the method for producing the first intermediate, volume segment V 2 comprises a first region and another region, wherein the relative ratio of the number of particles per unit area of at least one impurity in the first region to the number of particles per unit area of at least one impurity in the other region is equal to or greater than 10, more preferably equal to or greater than 15, even more preferably equal to or greater than 20, further preferably equal to or greater than 25, and even further preferably equal to or greater than 30. This preferred embodiment is the 40th embodiment of the present invention, which preferably depends on the 39th embodiment of the present invention.

[0148] In one aspect of the 40th embodiment, preferably, the relative ratio of the number of particles per unit area of at least one impurity in the first region to the number of particles per unit area of at least one impurity in the other region is equal to or less than 1000, more preferably equal to or less than 500, and even more preferably equal to or less than 250.

[0149] In a preferred embodiment of the method for producing the first intermediate, at least one of the following or all apply to volume segment V 2 :

[0150] a. The pressure is in the range of 80 kPa to 135 kPa, more preferably in the range of 95 kPa to 120 kPa, further preferably in the range of 100 kPa to 115 kPa, and even further preferably in the range of 104 kPa to 109 kPa;

[0151] b. The overpressure range is 2 kPa to 12 kPa, more preferably in the range of 4 kPa to 8 kPa, and further preferably in the range of 5 kPa to 7 kPa.

[0152] This preferred embodiment is the 41st embodiment of the present invention, which preferably depends on any one of the 26th to 40th embodiments of the present invention.

[0153] In one aspect of the 41st embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b.

[0154] In a preferred embodiment of the method for producing the first intermediate, the residence time of the first polyester in volume segment V 2 is in the range of 30 minutes to 270 minutes, more preferably in the range of 50 minutes to 250 minutes, and further preferably in the range of 80 minutes to 220 minutes. This preferred embodiment is the 42nd embodiment of the present invention, which preferably depends on any one of the 26th to 41st embodiments of the present invention.

[0155] In a preferred embodiment of the method for producing the first intermediate, the method further comprises the step of reducing at least one or all of the following, preferably in volume section V 2 :

[0156] a. The weight average molar mass of the first polyester;

[0157] b. The intrinsic viscosity of the first polyester.

[0158] This preferred embodiment is the 43rd embodiment of the present invention, which preferably depends on any one of the 1st to 42nd embodiments of the present invention.

[0159] In one aspect of the 43rd embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are for example a; b; a + b. In one aspect of the 43rd embodiment, it is preferred to perform at least one or all of steps a. and b. in the 43rd embodiment before contacting the first polyester with another organic compound.

[0160] In a preferred embodiment of the method for producing the first intermediate, at least one or all of the following apply:

[0161] a. The weight average molar mass of the first polyester is preferably reduced by at least 50%, more preferably at least 60%, even more preferably at least 70%, further preferably at least 75%, even further preferably at least 80%, particularly preferably at least 85% in volume section V 2 ;

[0162] b. The intrinsic viscosity of the first polyester is preferably reduced by at least 40%, more preferably at least 50%, even more preferably at least 60%, further preferably at least 70%, further preferably at least 75% in volume section V 2 ;

[0163] This preferred embodiment is the 44th embodiment of the present invention, which preferably depends on the 43rd embodiment of the present invention.

[0164] In one aspect of the 44th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are for example a; b; a + b. In one aspect of the 44th embodiment, it is preferred that the intrinsic viscosity of the first polyester is reduced by 97% or less, more preferably 95% or less, even more preferably 93% or less, and further preferably 90% or less. In one aspect of the 44th embodiment, it is preferred that the intrinsic viscosity of the first polyester is reduced by a value in the range of 70% to 80%. In one aspect of the 44th embodiment, it is preferred that the weight average molar mass of the first polyester is reduced by 97% or less, more preferably 95% or less, and further preferably 93% or less. In one aspect of the 44th embodiment, it is preferred to reduce the weight average molar mass of the first polyester by a value in the range of 85% to 93%.

[0165] In a preferred embodiment of the method for producing the first intermediate, after completion of the reduction step, preferably in volume section V 2 the first polyester has at least one or all of the following properties:

[0166] a. The intrinsic viscosity ranges from 0.08 dL / g to 0.45 dL / g, more preferably from 0.10 dL / g to 0.35 dL / g, even more preferably from 0.12 dL / g to 0.25 dL / g, and further preferably from 0.12 dL / g to 0.20 dL / g;

[0167] b. The weight-average molar mass ranges from 3000 Da to 7500 Da, more preferably from 3200 Da to 7300 Da, even more preferably from 3800 Da to 7100 Da, and further preferably from 4000 Da to 6900 Da.

[0168] This preferred embodiment is the 45th embodiment of the present invention, which preferably depends on any one of the 43rd to 44th embodiments of the present invention.

[0169] In one aspect of the 45th embodiment, all possible combinations of characteristics a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b. In one aspect of the 45th embodiment, the preferred characteristics a. and b. are the characteristics of the first polyester leaving volume section V 2 In one aspect of the 45th embodiment, the preferred weight-average molar mass ranges from 4000 Da to 5000 Da.

[0170] In a preferred embodiment of the method for producing the first intermediate, the first polyester is conveyed:

[0171] I. / When the first polyester has an intrinsic viscosity greater than or equal to Y IV,1 it is conveyed in a first direction at least partially opposite to the direction of gravity, where Y IV,1 is 0.10 dL / g, more preferably 0.15 dL / g, even more preferably 0.20 dL / g, and further preferably 0.30 dL / g; and

[0172] II. / When the first polyester has an intrinsic viscosity less than or equal to Y IV,2 it is conveyed in another direction at least partially along the direction of gravity, where Y IV,2 is 0.09 dL / g, more preferably 0.07 dL / g, and even more preferably 0.05 dL / g.

[0173] This preferred embodiment is the 46th embodiment of the present invention, preferably subordinate to any one of the 1st to 45th embodiments of the present invention.

[0174] In the 46th embodiment, Y 1,IV >Y 2,IV . In one aspect of the 46th embodiment, conveyance is preferably understood to mean at least one or all of the following:

[0175] Conveying a first polyester from a first volume segment to another volume segment (e.g., from volume segment V 1 to volume segment V 2 , from volume segment V 2 to volume segment V 3 ), and conveying the first polyester to pass through a volume segment (e.g., volume segment V 1 , volume segment V 3 ). In one aspect of the 46th embodiment, it is preferred to first convey the first polyester in a first direction and then convey the first polyester in another direction. In one aspect of the 46th embodiment, it is preferred to convey the first polyester in a first direction after contacting the first polyester with a first amount of a first organic compound in volume segment V 1 . In one aspect of the 46th embodiment, when the intrinsic viscosity of the first polyester is in the range of Y 2,IV to Y 1,IV , it is preferred to convey the first polyester in the first direction, the other direction, or both. In one aspect of the 46th embodiment, it is preferred that when the first polyester is conveyed in the first direction, at least a part of the organic compound (preferably the first organic compound) is conveyed in the opposite direction to the first direction. In one aspect of the 46th embodiment, it is preferred that when the first polyester is conveyed in the other direction, at least a part of the organic compound (preferably another organic compound) is conveyed in the other direction. In one aspect of the 46th embodiment, it is preferred that Y IV,1 and Y IV,2 have one of the following combinations of values in characteristics I. / and II. / : Y IV,1 is 0.10 dL / g and Y IV,2 is 0.09 dL / g; Y IV,1 is 0.15 dL / g, Y IV,2 is 0.07 dL / g; Y IV,1 is 0.20 dL / g, Y IV,2 is 0.05 dL / g; Y IV,1 is 0.30 dL / g, Y IV,2 is 0.05 dL / g; Y IV,1 is 0.10 dL / g, Y IV,2 is 0.05 dL / g; or Y IV,1 is 0.30 dL / g, Y IV,2 is 0.09 dL / g. In one aspect of the 46th embodiment, it is preferred that the conveyance of the first polyester in the first direction includes at least one or all of the following: from volume segment V1 Transported to volume section V 2 、Transported through volume section V 2 or both. In one aspect of the 46th embodiment, preferably transporting the first polyester in the other direction includes transporting through volume section V 3 . In one aspect of the 46th embodiment, preferably the first polyester is in the form of a plurality of fragments.

[0176] In a preferred embodiment of the method for producing the first intermediate, the method further includes transporting the first polyester to volume section V 3 . This preferred embodiment is the 47th embodiment of the present invention, which preferably depends on any one of the 1st to 46th embodiments of the present invention.

[0177] In one aspect of the 47th embodiment, preferably transporting the first polyester from volume section V 1 to volume section V 3 , more preferably via volume section V 2 . In other words, the first polyester can be transported from volume section V 1 to volume section V 3 without the first polyester passing through volume section V 2 . However, more preferably transporting the first polyester from volume section V 2 to volume section V 3 .

[0178] In a preferred embodiment of the method for producing the first intermediate, the other organic compound has at least one or all of the following characteristics:

[0179] a. Contains at least two hydroxyl groups, such as a diol having 2 hydroxyl groups, a triol having 3 hydroxyl groups;

[0180] b. The molar mass is at least 60 g / mol;

[0181] c. The boiling point is at least 192 °C, more preferably at least 195 °C.

[0182] This preferred embodiment is the 48th embodiment of the present invention, which preferably depends on any one of the 1st to 47th embodiments of the present invention.

[0183] Examples of the other organic compound include (mono)ethylene glycol, propylene glycol, and glycerol. In one aspect of the 48th embodiment, all possible combinations of features a. to c. are preferred aspects of this embodiment. These combinations are for example a; b; c; a + b; a + c; b + c; a + b + c. In one aspect of the 48th embodiment, it is particularly preferred that the other organic compound is (mono)ethylene glycol, more preferably monoethylene glycol. In one aspect of the 48th embodiment, it is particularly preferred that the other organic compound is not propylene glycol.

[0184] In a preferred embodiment of the method for producing the first intermediate product, another initial mixture (preferably located in volume section V 3 ) is stirred. This preferred embodiment is the 49th embodiment of the present invention, which preferably depends on any one of the 1st to 48th embodiments of the present invention.

[0185] In one aspect of the 49th embodiment, stirring is preferably carried out using a mechanical device designed and arranged for stirring, a non-mechanical device designed and arranged for stirring, or a combination thereof.

[0186] In a preferred embodiment of the method for producing the first intermediate product, preferably at the inlet end of volume section V 3 , the mass ratio of the first polyester to another organic compound in the other initial mixture is greater than 1.0. This preferred embodiment is the 50th embodiment of the present invention, which preferably depends on any one of the 1st to 49th embodiments of the present invention.

[0187] In one aspect of the 50th embodiment, preferably the inlet end is the position where the first polyester enters volume section V 3 .

[0188] In a preferred embodiment of the method for producing the first intermediate product, the temperature of the other initial mixture, preferably in volume section V 3 , is in the range of 180°C to 220°C, more preferably in the range of 180°C to 210°C. This preferred embodiment is the 51st embodiment of the present invention, which preferably depends on any one of the 1st to 50th embodiments of the present invention.

[0189] In a preferred embodiment of the method for producing the first intermediate product, the pressure in volume section V 3 is in the range of 75 kPa to 131 kPa, more preferably in the range of 90 kPa to 116 kPa, further preferably in the range of 95 kPa to 108 kPa, and even further preferably in the range of 98 kPa to 104 kPa. This preferred embodiment is the 52nd embodiment of the present invention, which preferably depends on any one of the 1st to 51st embodiments of the present invention.

[0190] In one aspect of the 52nd embodiment, preferably, the pressure in volume section V 3 is atmospheric pressure.

[0191] In a preferred embodiment of the method for producing the first intermediate product, the other initial mixture in volume section V 3The residence time therein is in the range of 100 minutes to 560 minutes, more preferably in the range of 140 minutes to 440 minutes, and even more preferably in the range of 170 minutes to 380 minutes. This preferred embodiment is the 53rd embodiment of the present invention, which preferably depends on any one of the 1st to 52nd embodiments of the present invention.

[0192] In a preferred embodiment of the method for producing the first intermediate product, the first intermediate mixture comprises at least 70 wt-%, more preferably at least 80 wt-%, even more preferably at least 85 wt-%, further preferably at least 90 wt-%, and further preferably at least 94 wt-% of the first intermediate product. This preferred embodiment is the 54th embodiment of the present invention, which preferably depends on any one of the 1st to 53rd embodiments of the present invention.

[0193] In the 54th embodiment, the wt-% is based on the total mass of the first intermediate mixture. In an alternative aspect of the 54th embodiment, the first intermediate mixture comprises the first intermediate product in the range of 70 wt-% to 99 wt-%, optionally in the range of 80 wt-% to 95 wt-%, and optionally in the range of 88 wt-% to 92 wt-%.

[0194] In a preferred embodiment of the method for producing the first intermediate product, at least 40 wt-%, more preferably at least 50 wt-%, even more preferably at least 60 wt-%, further preferably at least 65 wt-%, and even further preferably at least 70 wt-% of the first intermediate product is in the form of oligomers having 2 to 35 repeating units, more preferably 2 to 30 repeating units, even more preferably 2 to 25 repeating units, and further preferably 2 to 20 repeating units. This preferred embodiment is the 55th embodiment of the present invention, which preferably depends on any one of the 1st to 54th embodiments of the present invention.

[0195] In the 55th embodiment, the wt-% is based on the total mass of the first intermediate product in the first intermediate mixture. In one aspect of the 55th embodiment, preferably, at least 40 wt-%, more preferably at least 50 wt-%, even more preferably at least 60 wt-%, further preferably at least 65 wt-%, and even further preferably at least 70 wt-% of the first intermediate product is in the form of oligomers having the number of repeating units in at least one of the following ranges: 3 to 30, 4 to 30, 6 to 30, 8 to 30, 3 to 20, 4 to 20, 6 to 20. In one aspect of the 55th embodiment, preferably, at least 70 wt-% of the oligomers have the number of repeating units in the range of 2 to 35, more preferably in the range of 2 to 30, even more preferably in the range of 2 to 25, and further preferably in the range of 2 to 20. Preferred oligomers include repeating units of ethylene terephthalate. In one aspect of the 55th embodiment, preferably, at least 40 wt-%, more preferably at least 50 wt-%, even more preferably at least 60 wt-%, further preferably at least 65 wt-%, and even further preferably at least 70 wt-% of the first intermediate product is in the form of oligomers having the number of repeating units in the range of 2 to 15, more preferably in the range of 2 to 12, and further preferably in the range of 2 to 10.

[0196] In a preferred embodiment of the method for producing the first intermediate product, at least one or all of the following apply:

[0197] a. The first intermediate product contains 30 wt-% or less, more preferably 25 wt-% or less, even more preferably 20 wt-% or less, further preferably 15 wt-% or less, and even further preferably 10 wt-% or less of monomers;

[0198] b. The first intermediate product contains at least 70 wt-%, more preferably at least 75 wt-%, even more preferably at least 80 wt-%, further preferably at least 85 wt-%, and even further preferably at least 90 wt-% of oligomers.

[0199] This preferred embodiment is the 56th embodiment of the present invention, which preferably depends on any one of the 1st to 55th embodiments of the present invention.

[0200] In the 56th embodiment, the wt-% is based on the total mass of the first intermediate product in the first intermediate mixture. In one aspect of the 56th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b. For example, the first intermediate product contains 20 wt-% of monomers and 80 wt-% of oligomers. In the 56th embodiment, an example of the monomer is BHET. In the 56th embodiment, an example of the oligomer is a PET oligomer. In an alternative aspect of the 56th embodiment, the first intermediate product contains monomers in the range of 15 wt-% to 30 wt-%, and optionally contains monomers in the range of 20 wt-% to 25 wt-%. In an alternative aspect of the 56th embodiment, the first intermediate product contains oligomers in the range of 70 wt-% to 85 wt-%, and optionally contains oligomers in the range of 75 wt-% to 85 wt-%. In one aspect of the 56th embodiment, particularly preferred oligomers have 2 to 10 repeating units.

[0201] In a preferred embodiment of the method for producing the first intermediate product, at least one or all of the following apply:

[0202] a. The first intermediate product contains at least 20 wt-%, more preferably at least 30 wt-%, even more preferably at least 40 wt-%, further preferably at least 50 wt-%, and even further preferably at least 60 wt-% of monomers;

[0203] b. The first intermediate product contains at least 20 wt-%, preferably at least 30 wt-%, more preferably at least 40 wt-%, and further preferably at least 50 wt-% of oligomers.

[0204] This preferred embodiment is an alternative embodiment of the 56th embodiment of the present invention, which preferably depends on any one of the 1st to 55th embodiments of the present invention. In one aspect of the present invention, any one of the 57th to 106th embodiments of the present invention preferably depends on this alternative embodiment of the 56th embodiment of the present invention.

[0205] In an alternative 56th embodiment, the wt-% is based on the total mass of the first intermediate product in the first intermediate mixture. In an alternative 56th embodiment, an example of the monomer is BHET. In an alternative 56th embodiment, an example of the oligomer is a PET oligomer. In one aspect of the alternative 56th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b. In a preferred aspect of the alternative 56th embodiment, for feature a., the first intermediate product contains monomers in the range of 20 wt-% to 60 wt-%, more preferably in the range of 30 wt-% to 50 wt-%, and even more preferably in the range of 35 wt-% to 40 wt-%. In this aspect, it is preferred that the remaining wt-% of the first intermediate product consists of oligomers. In an aspect of the alternative 56th embodiment, the particularly preferred oligomers have 2 to 10 repeating units.

[0206] In a preferred embodiment of the method for preparing the first intermediate product, the first intermediate product has at least one or all of the following properties:

[0207] a. The intrinsic viscosity is in the range of 0.010 dL / g to 0.120 dL / g, more preferably in the range of 0.030 dL / g to 0.090 dL / g, even more preferably in the range of 0.040 dL / g to 0.070 dL / g, and even further preferably in the range of 0.045 dL / g to 0.065 dL / g;

[0208] b. The weight-average molar mass is in the range of 350 Da to 800 Da, more preferably in the range of 450 Da to 650 Da, and even more preferably in the range of 500 Da to 600 Da.

[0209] This preferred embodiment is the 57th embodiment of the present invention, which preferably depends on any one of the 1st to 56th embodiments of the present invention.

[0210] In one aspect of the 57th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b.

[0211] In a preferred embodiment of the method for producing the first intermediate product, at least one or all of the following apply:

[0212] a. The first intermediate mixture contains 20 wt-% or less, more preferably 15 wt-% or less, even more preferably 12 wt-% or less, further preferably 10 wt-% or less, and even further preferably 8 wt-% or less of another organic compound;

[0213] b. The first intermediate mixture contains less than 15 wt-%, more preferably less than 10 wt-%, and even more preferably less than 5 wt-% of a dicarboxylic acid, such as terephthalic acid.

[0214] This preferred embodiment is the 58th embodiment of the present invention, which preferably depends on any one of the 1st to 57th embodiments of the present invention.

[0215] In one aspect of the 58th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b. In the 58th embodiment, the wt-% is based on the total mass of the first intermediate mixture. In one aspect of the 58th embodiment, the other organic compound should preferably be understood as being free, i.e., not chemically bonded to the first intermediate by a covalent bond. In an alternative aspect of the 58th embodiment, the first intermediate mixture contains another organic compound in the range of 5 wt-% to 20 wt-%, optionally in the range of 7 wt-% to 15 wt-%, and optionally in the range of 9 wt-% to 12 wt-%.

[0216] In a preferred embodiment of the method for producing the first intermediate, the method further includes the step of transporting the first intermediate mixture, preferably from volume section V 3 , to volume section V 4 . This preferred embodiment is the 59th embodiment of the present invention, which preferably depends on any one of the 1st to 58th embodiments of the present invention.

[0217] In one aspect of the 59th embodiment, preferably, the intrinsic viscosity of the first intermediate increases by less than 5%, more preferably less than 3%, even more preferably less than 1%, and even further preferably less than 0.1% in volume section V 4 . In another aspect of the 59th embodiment, preferably, the intrinsic viscosity of the first intermediate decreases by less than 5%, more preferably less than 3%, even more preferably less than 1%, and even further preferably less than 0.1% in volume section V 4 . In another aspect of the 59th embodiment, preferably, the intrinsic viscosity of the first intermediate varies (neither increases nor decreases) by less than 5%, more preferably less than 3%, even more preferably less than 1%, and even further preferably less than 0.1% in volume cross-section V 4 .

[0218] In a preferred embodiment of the method for producing the first intermediate, the method further includes the step of adding the first particulate material to the first intermediate mixture, preferably in volume section V 4 . This preferred embodiment is the 60th embodiment of the present invention, which preferably depends on any one of the 1st to 59th embodiments of the present invention.

[0219] In one aspect of the 60th embodiment, preferably, the first particulate material is designed and arranged for adsorption. In another aspect of the 60th embodiment, preferably, the first particulate material is designed and arranged for decolorization. In another aspect of the 60th embodiment, preferably the first particulate material is porous. In one aspect of the 60th embodiment, particularly preferably, the first particulate material is designed and arranged for filtration, more preferably microfiltration. Microfiltration is the filtration of particles in the range of 0.5 μm to 10 μm. In one aspect of the 60th embodiment, preferably, the first particulate material is added after the reduction of the weight average molar mass of the first polyester.

[0220] In a preferred embodiment of the method for producing the first intermediate, the median pore diameter of the first particulate material is in the range of 5.0 μm to 20.0 μm, preferably in the range of 10.0 μm to 20.0 μm, and further preferably in the range of 15.0 μm to 18.0 μm. This preferred embodiment is the 61st embodiment of the present invention, which preferably depends on the 60th embodiment of the present invention.

[0221] In a preferred embodiment of the method for preparing the first intermediate, the first particulate material has a pore size distribution in which at least one mode is in the range of 8000 nm to 20000 nm, more preferably in the range of 10000 nm to 18000 nm, and further preferably in the range of 10000 nm to 15000 nm. This preferred embodiment is the 62nd embodiment of the present invention, which preferably depends on any one of the 60th to 61st embodiments of the present invention.

[0222] In a preferred embodiment of the method for producing the first intermediate, the first particulate material has a pore size distribution having at least two modes in the range of 8000 nm and 20000 nm, wherein

[0223] a. at least one mode is in the range of 8000 nm to 15000 nm, preferably in the range of 10000 nm to 15000 nm;

[0224] b. at least one mode is in the range of >15000 nm to 20000 nm, preferably in the range of 16000 nm to 18000 nm.

[0225] This preferred embodiment is the 63rd embodiment of the present invention, which preferably depends on any one of the 60th to 62nd embodiments of the present invention.

[0226] In one aspect of the 63rd embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are for example a; b; a + b. In one aspect of the 63rd embodiment, preferably, the mode in feature a. is the minor mode. In one aspect of the 63rd embodiment, preferably, the mode in feature b. is the major mode.

[0227] In a preferred embodiment of the method for producing a first intermediate, the first particulate material has a pore size distribution in which at least one first mode is in the range from 9000 nm to 15000 nm and at least one other mode is in the range from >15000 nm to 20000 nm, wherein the ratio of the first mode to the other mode is in the range from 0.30 to 1.00, preferably in the range from 0.40 to 0.90, and more preferably in the range from 0.45 to 0.85. This preferred embodiment is the 64th embodiment of the present invention, which preferably depends on any one of the 60th to 63rd embodiments of the present invention.

[0228] In a preferred embodiment of the method for producing a first intermediate, the first particulate material has at least one or all of the following properties:

[0229] a. For pores with diameters in the range from 9000 nm to 20000 nm, the cumulative pore volume is in the range from 0.6 cm 3 / g to 1.9 cm 3 / g, preferably in the range from 0.9 cm 3 / g to 1.7 cm 3 / g, more preferably in the range from 1.1 cm 3 / g to 1.5 cm 3 / g;

[0230] b. For pores with diameters in the range from 10000 nm to 15000 nm, the cumulative pore volume is in the range from 0.5 cm 3 / g to 1.4 cm 3 / g, preferably in the range from 0.6 cm 3 / g to 1.2 cm 3 / g, more preferably in the range from 0.8 cm 3 / g to 1.0 cm 3 / g;

[0231] c. For pores with diameters in the range from >15000 nm to 20000 nm, the cumulative pore volume is in the range from 0.10 cm 3 / g to 0.80 cm 3 / g, preferably in the range from 0.20 cm 3 / g to 0.60 cm 3 / g, more preferably in the range from 0.25 cm 3 / g to 0.40 cm 3 / g.

[0232] This preferred embodiment is the 65th embodiment of the present invention, which preferably depends on any one of the 60th to 64th embodiments of the present invention.

[0233] In one aspect of the 65th embodiment, all possible combinations of features a. to c. are preferred aspects of this embodiment. These combinations are, for example, a; b; c; a + b; a + c; b + c; a + b + c.

[0234] In a preferred embodiment of the method for producing the first intermediate product, the first particulate material has at least one or all of the following properties:

[0235] a. The permeability is in the range of 0.7 Darcy to 10.0 Darcy, preferably in the range of 1.5 Darcy to 7.5 Darcy, more preferably in the range of 3.0 Darcy to 5.0 Darcy, and further preferably in the range of 3.5 Darcy to 4.5 Darcy;

[0236] b. The median particle size is in the range of 25 μm to 60 μm, preferably in the range of 35 μm to 55 μm, more preferably in the range of 40 μm to 50 μm, and further preferably in the range of 43 μm to 50 μm.

[0237] This preferred embodiment is the 66th embodiment of the present invention, which preferably depends on any one of the 60th to 65th embodiments of the present invention.

[0238] In one aspect of the 66th embodiment, all possible combinations of features a and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b.

[0239] In a preferred embodiment of the method for producing the first intermediate product, the first particulate material is selected from activated carbon (e.g., activated carbon), activated clay, diatomaceous earth, perlite, bentonite, cellulose, and combinations of at least two of them. This preferred embodiment is the 67th embodiment of the present invention, which preferably depends on any one of the 60th to 66th embodiments of the present invention.

[0240] In one aspect of the 67th embodiment, it is particularly preferred that the first particulate material is diatomaceous earth.

[0241] In a preferred embodiment of the method for preparing the first intermediate product, the mass ratio of the first particulate material to the first intermediate mixture in volume segment V 4 is in the range of 5.0x10 -4 to 2.5x10 -3 and more preferably in the range of 1.0x10 -3 to 2.0x10 -3 and further preferably in the range of 1.2x10 -3 to 1.8x10 -3 This preferred embodiment is the 68th embodiment of the present invention, which preferably depends on any one of the 60th to 67th embodiments of the present invention.

[0242] In a preferred embodiment of the method for producing the first intermediate, at least one or all of the following apply:

[0243] a. Volume section V 4 The temperature of the first intermediate mixture therein ranges from 160 °C to 230 °C, more preferably from 170 °C to 220 °C, even more preferably from 180 °C to 215 °C, further preferably from 185 °C to 209 °C, and even further preferably from 190 °C to 205 °C;

[0244] b. Stir the first intermediate mixture in volume section V 4 Therein.

[0245] This preferred embodiment is the 69th embodiment of the present invention, which preferably depends on any one of the 59th to 68th embodiments of the present invention.

[0246] In one aspect of the 69th embodiment, all possible combinations of characteristics a and b are preferred aspects of the embodiment. These combinations are, for example: a; b; a + b. In one aspect of the 69th embodiment, it is preferred to use a mechanical device designed and arranged for stirring to stir the first intermediate mixture.

[0247] In a preferred embodiment of the method for preparing the first intermediate, the residence time of the first intermediate mixture in volume section V 4 Therein is 10 hours or less, more preferably 7 hours or less, and further preferably 5 hours or less. This preferred embodiment is the 70th embodiment of the present invention, which preferably depends on any one of the 59th to 69th embodiments of the present invention.

[0248] In an alternative aspect of the 70th embodiment, the residence time of the first intermediate mixture in volume section V 4 Therein is at least 0.1 hour, optionally at least 1 hour, and optionally at least 3.5 hours.

[0249] In a preferred embodiment of the method for producing the first intermediate, the method further includes the step of transporting the first intermediate mixture to a filtration device, preferably from volume section V 4 Transport. This preferred embodiment is the 71st embodiment of the present invention, which preferably depends on any one of the 1st to 70th embodiments of the present invention.

[0250] In a preferred embodiment of the method for producing the first intermediate, the filtration device is selected from leaf filters, thin plate clarifiers, candle filters, porous filters, sintered filters, wire meshes, rotary drum filters, and combinations of two or more thereof. This preferred embodiment is the 72nd embodiment of the present invention, which preferably depends on the 71st embodiment of the present invention.

[0251] In one aspect of the 72nd embodiment, the preferred filtration device is a leaf filter, more preferably a vertical leaf filter.

[0252] In a preferred embodiment of the method for producing the first intermediate product, the pressure in the filtration device is in the range of 80 kPa to 1000 kPa, more preferably in the range of 140 kPa to 800 kPa, even more preferably in the range of 170 kPa to 610 kPa, and further preferably in the range of 200 kPa to 545 kPa. This preferred embodiment is the 73rd embodiment of the present invention, which preferably depends on any one of the 71st to 72nd embodiments of the present invention.

[0253] In a preferred embodiment of the method for producing the first intermediate product, the temperature in the filtration device is in the range of 150 °C to 215 °C, more preferably in the range of 160 °C to 205 °C, even more preferably in the range of 165 °C to 200 °C, and further preferably in the range of 170 °C to 195 °C. This preferred embodiment is the 74th embodiment of the present invention, which preferably depends on any one of the 71st to 73rd embodiments of the present invention.

[0254] In a preferred embodiment of the method for producing the first intermediate product, the method further includes a step of precoating the filtration device, preferably using a first particulate material. This preferred embodiment is the 75th embodiment of the present invention, which preferably depends on any one of the 71st to 74th embodiments of the present invention.

[0255] In one aspect of the 75th embodiment, the precoating step is preferably performed before at least partially removing at least one or all of the following: at least one impurity, the first particulate material.

[0256] In a preferred embodiment of the method for producing the first intermediate product, the method further includes a step of at least partially removing at least one impurity from the first intermediate mixture, preferably using the filtration device. This preferred embodiment is the 76th embodiment of the present invention, which preferably depends on any one of the 1st to 75th embodiments of the present invention.

[0257] In one aspect of the 76th embodiment, it is preferred to remove the first particulate material from the first intermediate mixture at least partially, and more preferably using a filtration device. For example, at least one impurity and the first particulate material are removed at least partially. In one aspect of the 76th embodiment, the removed particles (e.g., at least one impurity, the first particulate material) preferably have a particle size greater than 100 nm, more preferably greater than 150 nm, and further preferably greater than 200 nm. In one aspect of the 76th embodiment, preferably, the removed particles (e.g., at least one impurity, the first particulate material) have a particle size of 50 μm or less, more preferably 20 μm or less, even more preferably 10 μm or less, and further preferably 5 μm or less.

[0258] In a preferred embodiment of the method for producing the first intermediate product, the method further comprises transporting the first intermediate mixture to volume section V 5 This preferred embodiment is the 77th embodiment of the present invention, which preferably depends on any one of the 1st to 76th embodiments of the present invention.

[0259] In one aspect of the 77th embodiment, it is preferred to transport the first intermediate mixture from volume section V 3 to volume section V 5 However, more preferably, the first intermediate mixture is transported from volume section V 3 to volume section V 5 via at least one or all of the following: volume section V 4 a filtration device. In this aspect, it is particularly preferred to transport the first intermediate mixture from the filtration device to volume section V 5

[0260] In a preferred embodiment of the method for producing the first intermediate product, the method further comprises the step of adjusting, preferably in volume section V 5 the L value of the Hunter Lab color coordinates of the first intermediate mixture such that L ≥ 65, more preferably L ≥ 70, and further preferably L ≥ 75. This preferred embodiment is the 78th embodiment of the present invention, which preferably depends on any one of the 1st to 77th embodiments of the present invention.

[0261] In one aspect of the 78th embodiment, preferably, the Hunter Lab color coordinates of the first intermediate mixture, preferably in volume section V 5 are adjusted such that L is in the range of 65 to 92, more preferably in the range of 70 to 86, and further preferably in the range of 75 to 82. In one aspect of the 78th embodiment, it is preferred to adjust the L and b coordinates of Hunter Lab at least partially simultaneously.

[0262] In a preferred embodiment of the method for producing the first intermediate, by adding at least one colorant to the first intermediate mixture, preferably in volume segment V 5 therein, the Hunter Lab color coordinates L, b or both are adjusted. This preferred embodiment is the 79th embodiment of the present invention, which preferably depends on any one of the 1st to 78th embodiments of the present invention.

[0263] Suitable colorants are well known to those skilled in the art and are commercially available from Avient Corporation (USA) and Clariant AG (Switzerland). In one aspect of the 79th embodiment, it is preferred to adjust at least partially simultaneously the L and b coordinates of Hunter Lab.

[0264] In a preferred embodiment of the method for producing the first intermediate, the amount of at least one colorant added to the first intermediate mixture is determined by at least one or all of the following:

[0265] a. Adding a red colorant in an amount less than 200 ppm wt, more preferably less than 100 ppm wt, even more preferably less than 50 ppm wt, further preferably less than 20 ppm wt, even further preferably less than 15 ppm wt, and particularly preferably less than 10 ppm wt;

[0266] b. Adding a blue colorant in an amount less than 300 ppm wt, more preferably less than 150 ppm wt, even more preferably less than 70 ppm wt, further preferably less than 30 ppm wt, even further preferably less than 20 ppm wt, and particularly preferably less than 15 ppm wt;

[0267] c. Adding a red colorant and a blue colorant, wherein the ratio of the red colorant to the blue colorant is in the range of 0.1 to 10.0, more preferably in the range of 0.1 to 6.0, even more preferably in the range of 0.1 to 3.0, further preferably in the range of 0.1 to 1.0, even further preferably in the range of 0.3 to 0.8, and particularly preferably in the range of 0.4 to 0.7.

[0268] This preferred embodiment is the 80th embodiment of the present invention, which preferably depends on the 79th embodiment of the present invention.

[0269] In the 80th embodiment, the ppm mass value is based on the total mass of the first intermediate mixture. In one aspect of the 80th embodiment, all possible combinations of features a. to c. are preferred aspects of this embodiment. These combinations are, for example, a; b; c; a + b; a + c; b + c; a + b + c. In one aspect of the 80th embodiment, for feature a., a red colorant is optionally added at least 1 ppm wt, optionally at least 2 ppm wt, optionally at least 3 ppm wt. In one aspect of the 80th embodiment, for feature b., a blue colorant is optionally added at least 0.8 ppm wt, optionally at least 1.8 ppm wt, optionally at least 2.7 ppm wt. In the 80th embodiment, for feature c., the ratio of the red colorant to the blue colorant is calculated by dividing the ppm wt of the added red colorant by the ppm wt of the added blue colorant. In a preferred aspect of the 80th embodiment, for feature c., both the red colorant and the blue colorant are added before any colorant is added, and the L value of the first intermediate mixture is preferably in the range of 80 to 90, more preferably in the range of 82 to 88. In a preferred aspect of the 80th embodiment, for feature c., both the red colorant and the blue colorant are added before any colorant is added, and the b value of the first intermediate mixture is preferably in the range of 0.8 to 2.0, more preferably in the range of 1 to 2.

[0270] In a preferred embodiment of the method for producing the first intermediate product, at least one colorant is selected from dyes, toners, pigments, and combinations of at least two of them. This preferred embodiment is the 81st embodiment of the present invention, which preferably depends on any one of the 79th to 80th embodiments of the present invention.

[0271] In one aspect of the 81st embodiment, particularly preferably, at least one colorant is a pigment, a dye, or a combination thereof. In this aspect, the pigment is more preferred than the dye. In another aspect of the 81st embodiment, preferably, at least one colorant is not an acid dye. In another aspect of the 81st embodiment, preferably, at least one colorant is a pigment with a particle size less than 20 microns, more preferably less than 10 microns, even more preferably less than 1 micron, and further preferably less than 0.5 micron.

[0272] In a preferred embodiment of the method for producing the first intermediate product, the first polyester is transported in volume section V 2 in a direction at least partially opposite to the direction of gravity. In one aspect of this embodiment, it is preferred that the transport direction is opposite to the direction of gravity. In a preferred embodiment of the method for producing the first intermediate product, volume section V 2 is arranged at least partially vertically, more preferably vertically. The at least partially vertical arrangement should preferably be understood as that the longest dimension (e.g., length) of volume section V 2 is not parallel to the ground. For example, if volume section V2 Arranged vertically, the volume segment V 2 The length is perpendicular to the ground.

[0273] In a preferred embodiment of the method for producing a first intermediate product, the intrinsic viscosity of the first intermediate product is in the volume range V 4 In a preferred embodiment of the method for producing a first intermediate product, the intrinsic viscosity of the first intermediate product is in the volume segment V 4 In a preferred embodiment of the method for producing a first intermediate product, the intrinsic viscosity of the first intermediate product is less than 5%, more preferably less than 3%, further preferably less than 1%, and even further preferably less than 0.1%. 4 The average change (neither increase nor decrease) is less than 5%, more preferably less than 3%, further preferably less than 1%, and even further preferably less than 0.1%.

[0274] The 82nd embodiment of the present invention is a method for producing another intermediate product, comprising the following steps:

[0275] a. providing a first intermediate mixture comprising a first intermediate product, wherein the first intermediate product can be obtained by a method for producing a first intermediate product according to the present invention, preferably a method according to any one of Embodiments 1 to 81 of the present invention;

[0276] b. Increasing the weight average molar mass of the first intermediate product in the first intermediate mixture, preferably in the volume segment V 6 to obtain another intermediate mixture comprising another intermediate product.

[0277] In an optional aspect of the 82nd embodiment, the first intermediate mixture comprises at least one or all of the following: a first organic compound, another organic compound. The first organic compound and / or another organic compound in the other intermediate mixture may be present due to, for example, one of the following reasons: the first organic compound and / or another organic compound is removed from another volume segment (e.g., volume segment V 5 ) is transported to volume segment V 6 ; The first organic compound and / or the other organic compound are bound and released during the increase in weight average molar mass. In another optional aspect of the 82nd embodiment, the other intermediate mixture comprises at least one or all of the following: the first organic compound, the other organic compound. In one aspect of the 82nd embodiment, preferably in the volume segment V 6At least partially remove at least one or all of the following: the first organic compound, another organic compound. In another aspect of the 82nd embodiment, preferably the other intermediate mixture contains less than 1 wt-%, more preferably less than 0.1 wt-%, and even more preferably less than 0.01 wt-% of at least one or all of the following based on the total mass of the other intermediate mixture: the first organic compound, another organic compound. In one aspect of the 82nd embodiment, preferably less than 20 wt-%, more preferably less than 10 wt-%, even more preferably less than 5 wt-%, and further preferably less than 1 wt-% of the original product is used to obtain the other intermediate product. The wt-% is based on the total mass of the first intermediate mixture. Here, the original product has the following characteristics: a.) is a monomer, oligomer, polymer, or a combination thereof, preferably the first polyester; b.) is obtained by chemical synthesis, where the chemical synthesis does not include depolymerization and solvolysis. An example of the original product is the BHET monomer obtained by esterifying terephthalic acid with ethylene glycol.

[0278] In a preferred embodiment of the method for producing the other intermediate product, the first intermediate mixture is provided by conveying it to volume section V 6 This preferred embodiment is the 83rd embodiment of the present invention, which preferably depends on the 82nd embodiment of the present invention.

[0279] In one aspect of the 83rd embodiment, preferably the first intermediate mixture is conveyed from volume section V 3 to volume section V 6 . However, more preferably, the first intermediate mixture is conveyed from volume section V 3 to volume section V 6 by at least one or all of the following: volume section V 4 , a filtration device, volume section V 5 . In this aspect, it is particularly preferred to convey the first intermediate mixture from volume section V 5 to volume section V 6 .

[0280] In a preferred embodiment of the method for producing the other intermediate product, at least one or all of the following are added to the first intermediate mixture:

[0281] a. An amount of catalyst in the range of 20 ppm to 600 ppm, more preferably in the range of 30 ppm to 500 ppm, and even more preferably in the range of 40 ppm to 400 ppm;

[0282] b. An amount of stabilizer in the range of 1 ppm to 120 ppm, more preferably in the range of 5 ppm to 100 ppm, even more preferably in the range of 10 ppm to 80 ppm, and further preferably in the range of 20 ppm to 60 ppm.

[0283] This preferred embodiment is the 84th embodiment of the present invention, which preferably depends on any one of the 82nd to 83rd embodiments of the present invention.

[0284] In the 84th embodiment, the ppm value is based on the total mass of the first intermediate mixture. In one aspect of the 84th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b. In one aspect of the 84th embodiment, the preferred catalyst is Sb 2 O 3 , tetrabutoxytitanium, PTO (K 2 TiO (C 2 H 4 ) 2 *2H 2 O) or a combination of at least two of them. In this aspect, Sb 2 O 3 is particularly preferred. In one aspect of the 84th embodiment, it is preferred to apply at least one or all of the following: adding the catalyst before the first intermediate mixture enters volume section V 6 ; adding the catalyst to the first intermediate mixture in volume section V 6 , preferably before increasing the weight-average molar mass of the first intermediate product. In one aspect of the 84th embodiment, the preferred stabilizers are diphenylamine, 4-aminobenzoic acid, orthophosphoric acid, or a combination of at least two of them. In one aspect of the 84th embodiment, it is preferred to apply at least one or all of the following: adding the stabilizer before the first intermediate mixture enters volume section V 6 ; adding the stabilizer to the first intermediate mixture in volume section V 6 preferably before increasing the weight-average molar mass of the first intermediate product.

[0285] In a preferred embodiment of the method for producing another intermediate product, at least one or all of the following apply to volume section V 6 :

[0286] a. The temperature is in the range of 260 °C to 295 °C, more preferably in the range of 268 °C to 289 °C, and further preferably in the range of 272 °C to 285 °C;

[0287] b. The pressure is equal to or less than 3.7 kPa, more preferably equal to or less than 3.3 kPa, and further preferably equal to or less than 2.8 kPa.

[0288] This preferred embodiment is the 85th embodiment of the present invention, which preferably depends on any one of the 83rd to 84th embodiments of the present invention.

[0289] In one aspect of the 85th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b. In one aspect of the 85th embodiment, the preferred pressure is in the range of 0.01 kPa to 3.70 kPa, more preferably in the range of 0.05 kPa to 3.30 kPa, and further preferably in the range of 0.10 kPa to 2.80 kPa.

[0290] In a preferred embodiment of the method for producing another intermediate product, the first intermediate mixture has a residence time in volume section V 6 of less than 750 minutes, more preferably less than 500 minutes, even more preferably less than 350 minutes, and further preferably less than 200 minutes. This preferred embodiment is the 86th embodiment of the present invention, which preferably depends on any one of the 83rd to 85th embodiments of the present invention.

[0291] In one aspect of the 86th embodiment, it is preferred that the first intermediate mixture has a residence time in volume section V 6 of 40 minutes or longer, more preferably 70 minutes or longer, and further preferably 150 minutes or longer.

[0292] In a preferred embodiment of the method for producing another intermediate product, the other intermediate product, preferably the other intermediate product leaving volume section V 6 has at least one or all of the following characteristics:

[0293] a. The intrinsic viscosity is in the range of 0.15 dL / g to 0.45 dL / g, more preferably in the range of 0.18 dL / g to 0.40 dL / g, and further preferably in the range of 0.20 dL / g to 0.30 dL / g;

[0294] b. The weight-average molar mass is in the range of 5000 Da to 30000 Da, more preferably in the range of 9000 Da to 24000 Da, even more preferably in the range of 12000 Da to 20000 Da, and further preferably in the range of 14000 Da to 16500 Da.

[0295] This preferred embodiment is the 87th embodiment of the present invention, which preferably depends on any one of the 82nd to 86th embodiments of the present invention.

[0296] In one aspect of the 87th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b.

[0297] In a preferred embodiment of the method for producing another intermediate product, the method further comprises conveying another intermediate mixture, preferably from volume section V 6 to volume section V 7 . This preferred embodiment is the 88th embodiment of the present invention, which preferably depends on any one of the 82nd to 87th embodiments of the present invention.

[0298] In a preferred embodiment of the method for producing another intermediate product, the method further comprises the step of further increasing the weight-average molar mass of another intermediate product in another intermediate mixture, preferably in volume section V 7 . This preferred embodiment is the 89th embodiment of the present invention, which preferably depends on any one of the 82nd to 88th embodiments of the present invention.

[0299] In a preferred embodiment of the method for producing another intermediate product, at least one or all of the following apply to volume section V 7 :

[0300] a. The temperature is in the range of 240 °C to 310 °C, more preferably in the range of 258 °C to 298 °C, and further preferably in the range of 264 °C to 288 °C;

[0301] b. The pressure is equal to or less than 0.4 kPa, more preferably equal to or less than 0.35 kPa, and further preferably equal to or less than 0.32 kPa.

[0302] This preferred embodiment is the 90th embodiment of the present invention, which preferably depends on any one of the 88th to 89th embodiments of the present invention.

[0303] In one aspect of the 90th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b. In one aspect of the 90th embodiment, the temperature given in the preferred embodiment is the temperature measured at the inlet of volume section V 7 , and more preferably the temperature measured at the inlet where another intermediate mixture enters volume section V 7 . In one aspect of the 90th embodiment, the preferred pressure is in the range of 0.001 kPa to 0.400 kPa, more preferably in the range of 0.005 kPa to 0.350 kPa.

[0304] In a preferred embodiment of the method for producing another intermediate product, another intermediate mixture is in volume section V 7The residence time therein is less than 300 minutes, more preferably less than 200 minutes, even more preferably less than 150 minutes, and further preferably less than 100 minutes. This preferred embodiment is the 91st embodiment of the present invention, which preferably depends on any one of the 88th to 90th embodiments of the present invention.

[0305] In one aspect of the 91st embodiment, preferably, the other intermediate mixture has a residence time in volume section V 7 of 10 minutes or longer, more preferably 25 minutes or longer, and further preferably 40 minutes or longer.

[0306] In a preferred embodiment of the method for producing another intermediate product, the other intermediate product, preferably the other intermediate product leaving volume section V 7 has at least one or all of the following characteristics:

[0307] a. The intrinsic viscosity is in the range of 0.50 dL / g to 0.80 dL / g, more preferably in the range of 0.57 dL / g to 0.75 dL / g, and further preferably in the range of 0.62 dL / g to 0.67 dL / g;

[0308] b. The weight-average molar mass is in the range of 40,000 Da to 60,000 Da, more preferably in the range of 44,000 Da to 54,000 Da, and further preferably in the range of 46,000 Da to 52,000 Da.

[0309] This preferred embodiment is the 92nd embodiment of the present invention, which preferably depends on any one of the 82nd to 91st embodiments of the present invention, more preferably according to any one of the 88th to 91st embodiments of the present invention.

[0310] In one aspect of the 92nd embodiment, all possible combinations of characteristics a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a + b.

[0311] In a preferred embodiment of the method for producing another intermediate product, the method further comprises the step of at least partially removing at least one organic compound, preferably in volume section V 6 and / or volume section V 7 or both. This preferred embodiment is the 93rd embodiment of the present invention, which preferably depends on any one of the 82nd to 92nd embodiments of the present invention.

[0312] In one aspect of the 93rd embodiment, it is preferred that at least one organic compound is at least one or all of the following: a first organic compound, another organic compound. In another aspect of the 93rd embodiment, it is preferred that at least one organic compound is at least partially removed from at least one or all of the following: a first intermediate mixture and another intermediate mixture. In another aspect of the 93rd embodiment, it is preferred that the first organic compound is at least partially removed by flash distillation. In one aspect of the 93rd embodiment, it is preferred that at least one organic compound is at least partially removed simultaneously with at least one or all of the following: increasing the weight-average molar mass of the first intermediate product and increasing the weight-average molar mass of the other intermediate product.

[0313] In a preferred embodiment of the method for producing another intermediate product, the other intermediate product is another polyester. This preferred embodiment is the 94th embodiment of the present invention, which preferably depends on any one of the 82nd to 93rd embodiments of the present invention.

[0314] In a preferred embodiment of the method for producing another intermediate product, the other polyester is selected from polyethylene terephthalate, polybutylene terephthalate, polylactide, polypropylene terephthalate, polyethylene naphthalate, polycarbonate, polyester carbonate, polyarylate, polyester resin (preferably unsaturated polyester resin), and combinations of two or more thereof. This preferred embodiment is the 95th embodiment of the present invention, which preferably depends on the 94th embodiment of the present invention.

[0315] In one aspect of the 95th embodiment, it is particularly preferred that the other polyester is polyethylene terephthalate.

[0316] In a preferred embodiment of the method for producing another intermediate product, the other intermediate product is in the form of a liquid (e.g., a melt or a molten polymer), particles, or a combination thereof. This preferred embodiment is the 96th embodiment of the present invention, which preferably depends on any one of the 82nd to 95th embodiments of the present invention.

[0317] In one aspect of the 96th embodiment, the particles are commonly referred to as chips. In one aspect of the 96th embodiment, it is preferred to obtain the particles by extruding and cooling the hot melt.

[0318] In a preferred embodiment of the method for producing another intermediate product, the other intermediate product undergoes at least one processing step to obtain a product. This preferred embodiment is the 97th embodiment of the present invention, which preferably depends on any one of the 82nd to 96th embodiments of the present invention.

[0319] In one aspect of the 97th embodiment, it is preferred that the other intermediate product is downstream of volume section V 6 and more preferably downstream of volume section V 7downstream thereof undergoes at least one processing step.

[0320] In a preferred embodiment of the method for producing another intermediate product, at least one processing step includes at least one or all of the following: cooling, spinning, texturing, coloring (preferably by adding at least one colorant), melting, injection molding, blow molding, coating (preferably spin coating), cutting, extrusion, or a combination of at least two of them. This preferred embodiment is the 98th embodiment of the present invention, which preferably depends on the 97th embodiment of the present invention.

[0321] The 99th embodiment of the present invention is a first intermediate product obtainable by the method for producing a first intermediate product according to the present invention, preferably according to any one of the 1st to 81st embodiments of the present invention.

[0322] The 100th embodiment of the present invention is another intermediate product obtainable by the method for producing another intermediate product according to the present invention, preferably according to the method of any one of the 82nd to 98th embodiments of the present invention.

[0323] In one aspect of the 100th embodiment, the another intermediate product is preferably another polyester.

[0324] In a preferred embodiment of the another intermediate product, the another intermediate product has at least one or all of the following characteristics:

[0325] a. The weight-average molar mass is in the range of 40,000 Da to 100,000 Da, more preferably in the range of 44,000 Da to 80,000 Da, and still more preferably in the range of 48,000 Da to 60,000 Da;

[0326] b. The intrinsic viscosity is in the range of 0.50 dL / g to 0.80 dL / g, more preferably in the range of 0.57 dL / g to 0.75 dL / g, and still more preferably in the range of 0.62 dL / g to 0.67 dL / g;

[0327] c. In Hunter Lab color coordinates, the L value is at least 48 and the b value is 6 or less.

[0328] This preferred embodiment is the 101st embodiment of the present invention, which preferably depends on the 100th embodiment of the present invention.

[0329] In one aspect of the 101st embodiment, all possible combinations of features a. to c. are preferred aspects of this embodiment. These combinations are, for example, a; b; c; a + b; a + c; b + c; a + b + c. In one aspect of the 101st embodiment, for feature c., preferably another intermediate product has an L value in the range of 45 to 75 in Hunter Lab color coordinates, more preferably in the range of 50 to 70, and further preferably in the range of 55 to 65. In one aspect of the 101st embodiment, for feature c., preferably another intermediate product has a b value in the range of 0 to 6 in Hunter Lab color coordinates, more preferably in the range of 1 to 5, and further preferably in the range of 2 to 4.

[0330] The 102nd embodiment of the present invention is a product comprising another intermediate product according to the present invention, preferably another intermediate product according to any one of the 100th to 101st embodiments of the present invention.

[0331] In a preferred embodiment of this product, the product is selected from the group consisting of yarns, textiles, molded articles (e.g., bottles), molding materials, films, sheets, granules, composite materials, foams, fibers, lubricants, adhesives, thickeners, suspending agents, flocculants, resins, plastics, coatings, building materials, absorbent materials, drugs, materials for controlled release of active substances, powders, and combinations of at least two or more thereof. This preferred embodiment is the 103rd embodiment of the present invention, which preferably depends on the 102nd embodiment of the present invention.

[0332] In one aspect of the 103rd embodiment, it is particularly preferred that the product is a yarn, and more preferably a yarn for textiles. Examples of yarns include fully drawn yarns, drawn textured yarns, and partially oriented yarns.

[0333] In a preferred embodiment of the product, the product has at least one or all of the following characteristics:

[0334] a. In Hunter Lab color coordinates, the L value is at least 62, more preferably at least 68, and further preferably at least 73;

[0335] b. In Hunter Lab color coordinates, the b value is at least 1, more preferably at least 2, and further preferably at least 3;

[0336] c. The tensile strength is above 1.5 g / Denier, preferably above 2.0 g / Denier, and further preferably in the range above 2.5 g / Denier;

[0337] d. The weight-average molar mass is in the range of 40,000 Da to 100,000 Da, more preferably in the range of 44,000 Da to 80,000 Da, and even more preferably in the range of 48,000 Da to 60,000 Da;

[0338] e. The intrinsic viscosity is in the range of 0.50 dL / g to 0.80 dL / g, more preferably in the range of 0.57 dL / g to 0.75 dL / g, and even more preferably in the range of 0.62 dL / g to 0.67 dL / g;

[0339] f. The elongation at break is in the range of 5% to 175%, more preferably in the range of 10% to 150%, and even more preferably in the range of 20% to 125%.

[0340] This preferred embodiment is the 104th embodiment of the present invention, which preferably depends on any one of the 102nd to 103rd embodiments of the present invention.

[0341] In one aspect of the 104th embodiment, all possible combinations of features a. to f. are preferred aspects of this embodiment. These combinations are, for example, a; b; c; d; e; f; a + b; a + c; a + d; a + e; a + f; b + c; b + d; b + e; b + f; c + d; c + e; c + f; d + e; d + f; e + f; a + b + c; a + b + d; a + b + e; a + b + f; a + c + d; a + c + e; a + c + f; a + d + e; a + d + f; a + e + f; b + c + d; b + c + e; b + c + f; b + d + e; b + d + f; b + e + f; c + d + e; c + d + f; c + e + f; d + e + f; a + b + c + d; a + b + c + e; a + b + c + f; a + b + d + e; a + b + d + f; a + b + e + f; a + c + d + e; a + c + d + f; a + c + e + f; a + d + e + f; b + c + d + e; b + c + d + f; b + c + e + f; b + d + e + f; c + d + e + f; a + b + c + d + e; a + b + c + d + f; a + b + c + e + f; a + b + d + e + f; a + c + d + e + f; b + c + d + e + f; a + b + c + d + e + f. In one aspect of the 104th embodiment, for feature a., if the product is yarn, preferably, the product has an L value in the range of 62 to 95, more preferably in the range of 68 to 90, and even more preferably in the range of 73 to 87 in Hunter Lab colorimetric coordinates. In one aspect of the 104th embodiment, for feature b., if the product is yarn, preferably, the product has a b value in the range of 1 to 7, more preferably in the range of 2 to 6, and even more preferably in the range of 3 to 5 in Hunter Lab colorimetric coordinates. In the 104th embodiment, the tensile strength and elongation at break are measured according to Standard ASTM D2256 / D2256M - 21.

[0342] The 105th embodiment of the present invention is the use of a first intermediate product of the present invention (preferably the first intermediate product according to the 99th embodiment of the present invention) for producing another intermediate product (preferably another polyester).

[0343] In one aspect of the 105th embodiment, preferably, the another intermediate product produced is according to any one of the 100th to 101st embodiments of the present invention.

[0344] The 106th embodiment of the present invention is the use of another intermediate product of the present invention (preferably according to any one of the 100th to 101st embodiments of the present invention) for producing a product, preferably a product produced according to any one of the 102nd to 104th embodiments of the present invention.

[0345] Detailed Description of the Invention

[0346] Throughout the document, the disclosure of a range should preferably be understood to include both endpoints of the range. In addition, the disclosure of each range in the document should preferably be understood to also disclose preferred sub-ranges, where one endpoint is excluded or both endpoints are excluded. For example, the disclosure of the range from 60°C to 75°C should be understood to disclose the range including both endpoints 60°C and 75°C. In addition, it should also be understood to disclose the range including endpoint 60°C but excluding endpoint 75°C, the range excluding endpoint 60°C but including endpoint 75°C, and the range excluding both endpoints 60°C and 75°C.

[0347] Throughout the document, preferred embodiments and preferred aspects that disclose two or more features with preferred ranges or alternatives should be understood to include all possible combinations of these features. For example, an embodiment where "wt-% a of feature A, more preferably wt-% b of feature A, and further preferably wt-% c of feature A has a length of x, more preferably the length of feature A is y, and further preferably the length of feature A is z" discloses all embodiments with the following combinations of features: a, x; a, y; a, z; b, x; b, y; b, z; c, x; c, y; c, z.

[0348] Some preferred embodiments and preferred aspects may include different combinations of features. If various combinations are listed, the combinations are separated by a semicolon (";"). For example, the list "a; a + b; a + c + d" should be understood to disclose an embodiment including feature "a", an embodiment including features "a" and "b", and an embodiment including features "a", "c", and "d".

[0349] The following abbreviations are used in the description: polyethylene terephthalate (PET), polyvinyl chloride (PVC), ethylene glycol (EG), monoethylene glycol (MEG), bis(2-hydroxyethyl) terephthalate (BHET).

[0350] Volume Segment

[0351] "Volume section" (e.g., V 1 、V 2 ) is preferably understood to refer to a volume that is designed and arranged to receive a certain amount of solid, liquid, gas, or a combination thereof. Examples of "volume section" include storage tanks, storage containers, reactors (e.g., depolymerization reactors), pipes, siphons, or a combination of two or more of them. The numbering of the volume section is preferably understood as a means of identifying the volume section. For example, if a method for producing a first intermediate product is carried out in volume sections V 1 and V 3 , this does not mean that the method is also carried out in volume section V 2 .

[0352] In one aspect of the present invention, it is preferred that at least two volume segments at least partially intersect spatially. For example, the first polyester contacts a first amount of a first organic compound in volume segment V 1 while reducing the weight-average molar mass of the first polyester in volume segment V 3 . If volume segments V 1 and V 3 both refer to the same internal volume of a reactor, then volume segments V 1 and V 3 intersect spatially. If two volume segments (e.g., a first volume segment and another volume segment) intersect spatially, then the volume segments differ from each other in that the difference in at least one physical parameter (e.g., temperature) in the volume segments is at least 15%. For example, the average temperature of the first volume segment is 60 °C while the average temperature of the other volume segment is 120 °C. If two volume segments (e.g., a first volume segment and another volume segment) intersect in space, then for example the transfer of a first initial mixture from the first volume segment to the other volume segment should preferably be understood to mean that at least one physical parameter (e.g., temperature) in the volume segments changes by at least 15%.

[0353] In another more preferred aspect of the present invention, the spatial intersection of at least two, more preferably at least three, even more preferably at least four, and further preferably all volume segments is less than 30%, more preferably less than 20%, and further preferably less than 10%. In this regard, it is preferred that at least two volume segments are located in the same container, such as a reactor or a storage tank. However, in this regard, it is more preferred that the volume segments are located in different containers, such as a reactor or a storage tank.

[0354] In one aspect of the present invention, it is preferred to transfer the first polyester from volume segment V 1 to volume segment V 2 . In this regard, it is preferred that at least one outlet through which the first polyester leaves volume segment V 1 is arranged at a position less than 50 cm, more preferably less than 40 cm, and further preferably less than 35 cm from the bottom of volume segment V 1 . In this regard, it is preferred that at least one inlet (e.g., an inlet of the first type) through which the first polyester enters volume segment V 2 is arranged at a position less than 50 cm, more preferably less than 40 cm, and further preferably less than 30 cm from the bottom of volume segment V 2 . The distance from the bottom of the volume segment to the inlet (or outlet) is measured from the bottom of the volume segment to the point closest to the bottom of the inlet (or outlet).

[0355] In one aspect of the present invention, it is preferred that at least one, more preferably at least two, even more preferably at least three, and still more preferably all volume segments are in fluid communication. In another aspect of the present invention, it is preferred that at least one or all of the following apply: volume segment V 1 is in fluid communication with volume segment V 2 ; volume segment V 2 is in fluid communication with volume segment V 3 ; volume segment V 3 is in fluid communication with volume segment V 4 ; volume segment V 4 is in fluid communication with volume segment V 5 ; volume segment V 5 is in fluid communication with volume segment V 6 ; volume segment V 6 is in fluid communication with volume segment V 7 ; volume segment V 1 is in fluid communication with volume segment V 3 ; volume segment V 3 is in fluid communication with volume segment V 5 ; volume segment V 3 is in fluid communication with volume segment V 7 ; volume segment V 5 is in fluid communication with volume segment V 7 ; volume segment V

[0356] In one aspect of the present invention, it is preferred that at least one, more preferably at least two, even more preferably at least three, and still more preferably all volume segments are in fluid communication with at least one filtration device. In one aspect of the present invention, it is preferred that at least one or all of the following apply: volume segment V 4 is in fluid communication with at least one filtration device; volume segment V 5 is in fluid communication with at least one filtration device.

[0357] In one aspect of the present invention, it is preferred that volume segment V 2 has a first region and another region. In this aspect, it is preferred that the another region is located downstream of the first region. In this aspect, it is preferred that the mass ratio of the first polyester to the first organic compound in the first region is different from the mass ratio of the first polyester to the first organic compound in the another region. Still more preferably, the mass ratio of the first polyester to the first organic compound in the first region is less than the mass ratio of the first polyester to the first organic compound in the another region.

[0358] In one aspect of the present invention, it is preferred that volume segment V 2 has a first region and another region, wherein the first region and the another region are not adjacent to each other.

[0359] In another aspect of the present invention, it is preferred that volume segment V 2having a first region and another region, wherein the first region and the first region are adjacent to each other. In this regard, preferably the first region and the other region are at least partially separated by a boundary. Preferred boundaries are physical boundaries and imaginary boundaries, or combinations thereof. Preferably the imaginary boundary is defined as the location where a measurable physical property changes rapidly in the volume segment V 2 where the physical property of the volume segment V 2 the mass ratio of the first polyester to the first organic compound changes rapidly. The rapid change is preferably defined as the value of the physical property changing by at least 50%, more preferably at least 60%, and further preferably at least 70% within a distance of less than 50 cm, more preferably less than 30 cm, and further preferably less than 15 cm. For example, the imaginary boundary can be defined by the liquid level of the first organic compound in the volume segment V 2 An example of a physical boundary between the first region and the other region is a sieve.

[0360] In one aspect of the present invention, preferably, the volume segment V 1 is adjusted and arranged for at least one or all of the following: removing at least one impurity from the surface of the first polyester (e.g., removing a label from a PET sheet), removing at least one impurity from the first initial mixture, and removing at least one impurity from the raw material (e.g., dust).

[0361] In one aspect of the present invention, preferably the volume segment V 2 is designed and arranged for at least one or all of the following: removing at least one impurity from a mixture containing the first polyester and the first organic compound, at least partially depolymerizing the first polyester (preferably by solvolysis), and embrittling the first polyester. "Embrittling" preferably should be understood as a process of making the first polyester more brittle. For example, if the first polyester is in the form of a PET sheet, the force required to break the sheet into smaller pieces after embrittlement is less than the force required to break the PET sheet into smaller pieces before embrittlement.

[0362] In one aspect of the present invention, preferably, the volume segment V 3 is designed and arranged for at least partially depolymerizing the first polyester, preferably using solvolysis.

[0363] In one aspect of the present invention, preferably, the volume segment V 4 is adapted and arranged for at least one or all of the following: mixing a liquid with particulate material, and heating the liquid.

[0364] In one aspect of the present invention, preferably, the volume segment V 5 is designed and arranged for at least one or all of the following: storing a liquid, maintaining the temperature of the liquid, heating the liquid, or a combination of at least two of them.

[0365] In one aspect of the present invention, preferably, the volume section V 6 is designed and arranged to polymerize at least one or all of the following substances, more preferably by polycondensation: monomers and oligomers.

[0366] In one aspect of the present invention, preferably, the volume section V 7 is designed and arranged to polymerize at least one or all of the following substances, more preferably by polycondensation: monomers and oligomers.

[0367] In one aspect of the present invention, preferably, A1.) The first polyester is contacted with an additional amount of a first organic compound in the volume section V 2 , and A2.) The weight-average molar mass of the first polyester is reduced in the volume section V 2 . In this regard, preferably, steps A1.) and A2.) are carried out at least partially simultaneously.

[0368] In one aspect of the present invention, preferably, B1.) The first polyester is contacted with another organic compound in the volume section V 3 , and B2.) The weight-average molar mass of the first polyester is reduced in the volume section V 3 . In this regard, preferably, steps B1.) and B2.) are carried out at least partially simultaneously.

[0369] Fluid Communication

[0370] The phrase "in fluid communication" should preferably be understood to mean the following: If a first component (e.g., the volume section V 1 ) and another component (e.g., the volume section V 2 ) are in fluid communication with each other, then a fluid, gas, or a combination thereof can flow from the first component to the other component, or from the other component to the first component, or both. It should also preferably be understood that if components are "in fluid communication" with each other, this does not mean that the components must be adjacent to each other. For example, another component is arranged between the first component and the other component. If, for example, a fluid can flow from the first component to the other component through this other component, then the first component and the other component are "in fluid communication".

[0371] In one aspect of the present invention, if a first component is in fluid communication with another component, and that other component is in fluid communication with a further component, then this should preferably be understood to mean that the first component and the further component are in fluid communication with each other.

[0372] In one aspect of the present invention, preferably, at least one or all of the following can be transported between two components in fluid communication with each other: solids, mixtures of solids and fluids, mixtures of solids and gases, and mixtures of solids, liquids, and gases. For example, an Archimedes screw, a siphon, or a combination thereof can be used to transport a mixture containing PET flakes and MEG between two volume segments in fluid communication with each other.

[0373] Mass Ratio of the First Polyester to the Organic Compound

[0374] The mass ratio of the first polyester to the organic compound (e.g., the first organic compound, another organic compound) is preferably understood to be the mass ratio of the first polyester to the free organic compound.

[0375] Raw Materials

[0376] In one aspect of the present invention, a "feedstock" containing the first polyester is provided. In this aspect, the feedstock may optionally contain one or more other components, such as at least one impurity. In various and preferred aspects of the present invention, the first polyester is contacted with an organic compound (e.g., the first organic compound, another organic compound). This contact of the first polyester with the organic compound is preferably understood to include the following two cases: a.) Before contacting with the organic compound, at least one other component of the feedstock is at least partially separated from the first polyester (i.e., the initially provided feedstock no longer exists or its composition has been changed), and it is the first polyester (where at least one other component is at least partially removed) that contacts the organic compound; b.) The feedstock contacts the organic compound without at least partially removing at least one other component. The above preferably applies, with necessary modifications, to the transportation of the first polyester.

[0377] For example, the first polyester contacts the first organic compound in volume segment V 1 . The first polyester is provided as part of a feedstock that also contains impurities. The impurities are not removed before contact. That is, the contact of the first polyester with the first organic compound is equivalent to the contact of the feedstock with the first organic compound. In volume segment V 1 , the impurities are partially removed, and the first polyester, together with some of the unremoved impurities, is transported to volume segment V 2 . Here, the first polyester and the transported impurities are no longer equivalent to the initially provided feedstock.

[0378] Multiple Fragments

[0379] "Product article" is preferably understood to include an article comprising a first polyester. Examples of product articles include: articles that have been used at least once, preferably by a consumer (e.g., post-consumer waste); articles that have been produced but never used (e.g., articles rejected due to non-compliance with quality requirements); articles that are by-products of a production process (e.g., scrap). Examples of product articles include bottles and thermoformed articles. In a preferred aspect of the present invention, the product article is a bottle and a thermoformed article, more preferably a bottle.

[0380] In one aspect of the present invention, it is preferred that the first polyester in the raw material is in the form of a plurality of fragments. In this aspect, it is preferred to obtain the plurality of fragments by processing the product article. Examples of processing the product article include shredding, milling, or a combination thereof. For example, a PET bottle is provided and first shredded to obtain PET flakes, and then the PET flakes are milled. In another example, a textile containing PET is provided and the textile is shredded to obtain textile fragments. In this aspect where the raw material is in the form of a plurality of fragments, it is preferred to process the product article to obtain a plurality of fragments, wherein at least 50%, more preferably at least 60%, and further preferably at least 70% of the fragments have at least one physical dimension that differs from the average value of at least one physical dimension by less than 50%, more preferably less than 40%, and further preferably less than 30%. Examples of at least one physical dimension are the width, length, and thickness of the fragment. For example, at least 70% of the fragments have a width that differs from the average width of the plurality of fragments by less than 40%. In another aspect of the present invention, it is preferred to process the product before contacting the raw material with a first amount of a first organic compound.

[0381] The "fragments" of the first polyester preferably have physical dimensions (e.g., length, width, thickness) that are all below an upper limit value. Preferably, the upper limit value is less than 5 cm, more preferably less than 4 cm, and further preferably less than 3 cm. An example of a plurality of "fragments" is PET flakes, which are well known to those skilled in the art of recycling.

[0382] The "first dimension" of the fragment is preferably understood to be the width, length, or both of the fragment. The "length" of the fragment is preferably understood to refer to the largest dimension of the fragment. The "width" of the fragment is preferably understood to refer to the second largest dimension of the fragment. The "thickness" of the fragment is preferably understood to refer to the smallest dimension of the fragment.

[0383] In a preferred aspect of the present invention, the geometry of the fragment is not limited. For example, the fragment can be flat, parabolic, or irregular in shape.

[0384] In one aspect of the present invention, it is preferred that the plurality of fragments include a plurality of fragments of a first type and a plurality of fragments of other types. The "fragments of the first type" should preferably be understood as fragments having a maximum thickness of less than 1.0 mm. The "fragments of other types" should preferably be understood as fragments having a maximum thickness of 1.0 mm or greater. Examples of the "fragments of the first type" are fragments obtained by crushing the wall of a PET beverage container. Examples of the "fragments of other types" are fragments obtained by crushing the bottom of a PET beverage container.

[0385] In the preferred embodiments and the specification, if "fragments" are mentioned, it should preferably be understood as the fragments constituting the plurality of fragments.

[0386] At Least One Impurity

[0387] In one aspect of the present invention, it is preferred that the raw material contains at least one impurity. In this aspect, it is preferred that the raw material contains less than 3.0 wt-%, more preferably less than 2.0 wt-%, even more preferably less than 1.0 wt-%, further preferably less than 0.5 wt-%, and even further preferably less than 0.1 wt-% of at least one impurity based on the total mass of the raw material.

[0388] Examples of the "at least one impurity" include adhesives, paper, sand (e.g., in the form of dust), stones (e.g., gravel), wood, food residues, at least one metal (e.g., Sb, Fe, Ti, Al), at least one polyolefin (e.g., high-density polyethylene, polyethylene, polypropylene), polystyrene, polyvinyl chloride, fuels (e.g., paraffin, gasoline, diesel), or a combination of two or more of them. An example of at least one polyolefin impurity is a bottle cap.

[0389] In a preferred aspect of the present invention, wherein the first polyester in the raw material is provided in the form of a plurality of fragments, examples of the at least one impurity are one or all of the following: at least one impurity adhering to the outer surface of the fragments (e.g., a label adhering to the outer surface of a PET sheet), at least one impurity mixed with the plurality of fragments (e.g., gravel mixed with a PET sheet), or a combination thereof.

[0390] In one aspect of the present invention, it is preferred to wash the raw material, preferably using at least one or all of the following: water, alkaline washing. The preferred alkaline washing includes sodium hydroxide. In this regard, preferably, the raw material is washed before contacting the raw material with a first amount of a first organic compound. For example, according to the present invention, the raw material used in the method for producing a first intermediate product is washed before contacting it with a first amount of a first organic compound.

[0391] Number of Particles per Unit Area

[0392] In one aspect of the present invention, it is preferred to apply at least one or all of the following:

[0393] a. The number of particles per unit area of at least one impurity in volume segment V 1 is at least 100,000 particles / cm 2 , more preferably at least 1,000,000 particles / cm 2 , and even more preferably at least 3,000,000 particles / cm 2 ;

[0394] b. The number of particles per unit area of at least one impurity in the first region of volume segment V 2 is in the range of 3,000 particles / cm 2 to 350,000 particles / cm 2 , more preferably in the range of 30,000 particles / cm 2 to 250,000 particles / cm 2 , and even more preferably in the range of 100,000 particles / cm 2 to 200,000 particles / cm 2 ;

[0395] c. The number of particles per unit area of at least one impurity in another region of volume segment V 2 is in the range of 100 particles / cm 2 to 12,000 particles / cm 2 , more preferably in the range of 500 particles / cm 2 to 6,000 particles / cm 2 , and even more preferably in the range of 1,000 particles / cm 2 to 2,000 particles / cm 2 .

[0396] In the above aspects, all possible combinations of features a. to c. are preferred. These combinations are, for example, a; b; c; a + b; a + c; b + c; a + b + c.

[0397] Inlet

[0398] "The first type of inlet" is preferably understood as an inlet that is designed and arranged to allow the first polyester to enter the volume segment. For example: The volume segment is a reactor, and the first type of inlet is an opening on the side of the reactor.

[0399] "Another type of inlet" is preferably understood as an inlet that is designed and arranged to allow an organic compound (e.g., the first organic compound) to enter the volume segment. The preferred another type of inlet is designed and arranged to allow the organic compound to enter the volume segment in the form of a gas (e.g., vapor). An example of another type of inlet is a gas nozzle, such as a high-pressure gas nozzle.

[0400] "Another type of inlet" is preferably understood to refer to an inlet that is designed and arranged to allow an organic compound (e.g., a first organic compound) to enter the volume section. A preferred another type of inlet is designed and arranged to allow the organic compound to enter the volume section in liquid form. An example of another type of inlet is a nozzle, such as a nozzle designed and arranged to spray a liquid.

[0401] Molar Mass

[0402] In one aspect of the present invention, preferably, before the first polyester contacts the first amount of the first organic compound, its number average molar mass is in the range of 12,000 Da to 18,500 Da, more preferably in the range of 12,700 Da to 17,700 Da, and further preferably in the range of 13,200 Da to 17,200 Da.

[0403] In one aspect of the present invention, preferably, the number average molar mass of the first polyester leaving the volume section V 1 is in the range of 10,100 Da to 21,800 Da, more preferably in the range of 10,900 Da to 21,100 Da, and further preferably in the range of 11,400 Da to 20,600 Da.

[0404] In one aspect of the present invention, preferably, the number average molar mass of the first polyester present in the volume section V 2 is in the range of 500 Da to 2500 Da, more preferably in the range of 700 Da to 2000 Da, and further preferably in the range of 1000 Da to 1500 Da.

[0405] In one aspect of the present invention, preferably, the number average molar mass of the first intermediate is in the range of 200 Da to 600 Da, more preferably in the range of 300 Da to 500 Da, and further preferably in the range of 350 Da to 400 Da.

[0406] In one aspect of the present invention, preferably, the number average molar mass of another intermediate leaving the volume section V 6 is in the range of 200 Da to 600 Da, more preferably in the range of 3000 Da to 6500 Da, and further preferably in the range of 3700 Da to 5500 Da.

[0407] In one aspect of the present invention, preferably, the number average molar mass of another intermediate leaving the volume section V 7 is in the range of 6500 Da to 10500 Da, more preferably in the range of 7500 Da to 10000 Da, and further preferably in the range of 8000 Da to 9500 Da.

[0408] In one aspect of the present invention, the first polyester is preferably in the form of a plurality of first-type fragments and a plurality of another-type fragments. In this aspect, it is preferred that at least one or all of the following apply:

[0409] A.) Before contacting with a first amount of a first organic compound, the weight-average molar mass of the plurality of first-type fragments is in the range of 55,000 Da to 72,000 Da, more preferably in the range of 60,000 Da to 68,000 Da, and still more preferably in the range of 62,000 Da to 66,000 Da;

[0410] B.) Before contacting with a first amount of a first organic compound, the weight-average molar mass of the plurality of another-type fragments is in the range of 50,000 Da to 70,000 Da, more preferably in the range of 55,000 Da to 64,000 Da, and still more preferably in the range of 57,000 Da to 62,000 Da;

[0411] C.) The mass-average molar mass of the plurality of first-type fragments leaving volume section V 1 is in the range of 47,000 Da to 58,000 Da, more preferably in the range of 49,000 Da to 56,500 Da, and still more preferably in the range of 51,000 Da to 54,500 Da;

[0412] D.) The mass-average molar mass of the plurality of another-type fragments leaving volume section V 1 is in the range of 44,000 Da to 77,000 Da, more preferably in the range of 48,000 Da to 73,000 Da, and still more preferably in the range of 50,000 Da to 71,000 Da;

[0413] E.) The mass-average molar mass of the plurality of first-type fragments leaving volume section V 2 is in the range of 3,700 Da to 6,000 Da, more preferably in the range of 4,100 Da to 5,300 Da;

[0414] F.) The mass-average molar mass of the plurality of another-type fragments leaving volume section V 2 is in the range of 2,300 Da to 7,500 Da, more preferably in the range of 3,200 Da to 7,200 Da.

[0415] In the above aspects, all possible combinations of features A. to F. are preferred. These combinations are, for example, a; b; c; d; e; f; a + b; a + c; a + d; a + e; a + f; b + c; b + d; b + e; b + f; c + d; c + e; c + f; d + e; d + f; e + f; a + b + c; a + b + d; a + b + e; a + b + f; a + c + d; a + c + e; a + c + f; a + d + e; a + d + f; a + e + f; b + c + d; b + c + e; b + c + f; b + d + e; b + d + f; b + e + f; c + d + e; c + d + f; c + e + f; d + e + f; a + b + c + d; a + b + c + e; a + b + c + f; a + b + d + e; a + b + d + f; a + b + e + f; a + c + d + e; a + c + d + f; a + c + e + f; a + d + e + f; b + c + d + e; b + c + d + f; b + c + e + f; b + d + e + f; c + d + e + f; a + b + c + d + e; a + b + c + d + f; a + b + c + e + f; a + b + d + e + f; a + c + d + e + f; b + c + d + e + f; a + b + c + d + e + f.

[0416] Direction Relative to Gravity

[0417] If a direction (e.g., a first direction) is "at least partially opposite to the direction of gravity", it is preferably understood that: if the direction is decomposed into three perpendicular components, the orientation of the component parallel to the direction of gravity is such that the component is opposite to the direction of gravity. If a direction (e.g., a first direction) is "at least partially along the direction of gravity", it is preferably understood that: if the direction is decomposed into three perpendicular components, the orientation of the component parallel to the direction of gravity is such that the component is along the direction of gravity, i.e., pointing in the same direction as gravity.

[0418] Stirring in the Volume Segment

[0419] Stirring in the volume section is preferably carried out using a mechanical device suitable for stirring, a non - mechanical device suitable for stirring, or a combination thereof. Examples of suitable mechanical devices include agitators, such as vertical blade agitators, turbines, impellers, and propellers. Examples of suitable non - mechanical devices include injecting at least one fluid (e.g., in the form of a gas, a liquid, or a combination thereof) into the volume section (preferably under pressure) and ultrasonic waves. For example, another organic compound is injected as a liquid through a nozzle into volume section V 3 .

[0420] Organic Compound

[0421] Preferred "organic compounds" (e.g., the first organic compound, another organic compound) are compounds suitable for reducing the molar mass (e.g., weight-average molar mass, number-average molar mass) of the first polyester, preferably by solvolysis. For example, if the first polyester is PET, (mono)ethylene glycol, alcohol, or methanol can be used to reduce the weight-average molar mass of the first polyester through a solvolysis process. Preferred "organic compounds" (e.g., the first organic compound, another organic compound) are selected from (mono)ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, polypropylene glycol, alcohol, methanol, and combinations of at least two of them, where (mono)ethylene glycol is more preferred and monoethylene glycol is particularly preferred.

[0422] "Free" organic compounds should preferably be understood to refer to organic compounds that are not chemically bonded by covalent bonds to, for example, the first polyester, the first intermediate, or another intermediate. "Free" organic compounds are the opposite of "bound" organic compounds, which are chemically bonded by covalent bonds to, for example, the first polyester, the first intermediate, or another intermediate. For example, during the solvolysis of PET using MEG, some MEG is chemically bonded to PET oligomers. This bound MEG is not free MEG.

[0423] In one aspect of the present invention, it is preferred that the first organic compound and another organic compound are the same organic compound. For example, preferably, both the first organic compound and another organic compound are (mono)ethylene glycol.

[0424] Initial Mixture

[0425] In one aspect of the present invention, it is preferred that the first initial mixture includes the first polyester and the first organic compound. In one aspect of the present invention, it is preferred that the further initial mixture includes the first polyester and another organic compound. In this aspect, it is further preferred that the further initial mixture further includes the first organic compound. In one aspect of the present invention, it is preferred that another initial mixture includes the first polyester and the first organic compound.

[0426] First Particle Material

[0427] The first particulate material suitable for the present invention can be purchased from, for example, Merck KGaA (Germany) and Donau Carbon GmbH (Germany).

[0428] The "mode" of the first particulate material is a well-known measurement method of statistical distribution. The mode of the first particulate material will be further described below in conjunction with Figure 8 Further description.

[0429] Further Aspects and Definitions

[0430] In one aspect of the present invention, the starting material preferably contains less than 5 wt-%, more preferably less than 1 wt-%, and even more preferably less than 0.1 wt-% of a colorant. For example, the starting material contains PET flakes obtained by crushing colorless bottles. In one aspect of the present invention, the starting material preferably contains less than 5 wt-%, more preferably less than 1 wt-%, and even more preferably less than 0.1 wt-% of colored fragments.

[0431] In one aspect of the present invention, it is preferred that the methods of the present invention are operated continuously, semi-continuously or batchwise. Examples of these methods are "the method for producing a first intermediate" and "the method for producing another intermediate".

[0432] Preferred examples of "the method for producing a first intermediate" are those in which the first intermediate is produced by recycling a first polyester. Preferred examples of "the method for producing another intermediate" are those in which the other intermediate is produced by recycling a first polyester.

[0433] The process step of "contacting" a component (e.g., a first polyester) with an organic compound preferably comprises at least one or all of the following: the process step of mixing the organic compound with the component (e.g., mixing the organic compound and the component in a volume section using a stirring device); the process step of keeping the organic compound and the component in contact with each other (e.g., the component and the organic compound form a mixture, the component is suspended in the organic compound, or the component is at least partially dissolved in the organic compound); the process step of passing the organic compound through the component (e.g., passing steam through a porous component, or the component is in the form of multiple fragments and steam is passed between the fragments); or a combination of at least two or more of them.

[0434] The process step of "reducing the weight-average molar mass of the first polyester" preferably comprises at least one or all of the following: at least partially depolymerizing the first polyester (e.g., by solvolysis); heating the first polyester; photodegrading the first polyester; shearing the first polyester; or a combination of at least two or more of them.

[0435] In one aspect of the present invention, it is particularly preferred to reduce the weight-average molar mass of the first polyester by solvolysis. Examples of solvolysis include hydrolysis, glycolysis, alcoholysis, and ammonolysis. For example, if the first polyester is PET, water can be used to depolymerize PET into terephthalic acid and ethylene glycol (hydrolysis). For example, if the first polyester is PET, methanol can be used to depolymerize PET into dimethyl terephthalate and ethylene glycol (methanolysis). For example, if the first polyester is PET, (mono)ethylene glycol can be used to depolymerize PET into BHET and other PET glycolysis products (glycolysis). In this regard, glycolysis is particularly preferred.

[0436] The process step of "increasing the weight-average molar mass of the intermediate product" (e.g., the first intermediate product or another intermediate product) preferably includes at least one or all of the following: at least partially polymerizing the intermediate product; crosslinking the intermediate product; transesterifying the intermediate product; or a combination of at least two or more of them. In one aspect of the present invention, it is particularly preferred to increase the weight-average molar mass of the intermediate product by at least partially polymerizing the intermediate product. In this regard, polycondensation is preferred.

[0437] "Intrinsic viscosity" should preferably be understood as the average intrinsic viscosity.

[0438] "The first direction" is preferably understood as a direction that is at least partially opposite to the direction of gravity. "The other direction" is preferably understood as a direction that is at least partially along the direction of gravity.

[0439] "Ambient pressure" in the volume section is preferably understood as the pressure in the headspace of the volume section. "Overpressure" in the volume section is preferably understood as the pressure difference relative to the ambient pressure (e.g., the atmospheric pressure at the position of the volume section).

[0440] "Repeating unit" should preferably be understood as a part of a polymer, the repetition of which generates a polymer chain. For example, a polymer is formed by connecting "repeating units" together. "Dimer" should preferably be understood as a chain composed of two "repeating units". "Trimer" should preferably be understood as a chain composed of three "repeating units". In one aspect of the present invention, the preferred repeating unit has the following form

[0441]

[0442] "The first intermediate product" should preferably be understood as a product obtained by reducing the weight-average molar mass of the first polyester. Examples of "the first intermediate product" are oligomers of the first polyester, monomers of the first polyester, or combinations thereof. In one aspect of the present invention, it is preferred that "the first intermediate product" includes at least one or all of the following: monomers of the first polyester, oligomers of the first polyester, or both.

[0443] "Oligomer" should preferably be understood as a chain of repeating units, where the number of repeating units does not exceed 50.

[0444] Test Method

[0445] The following test methods are used within the scope of the present invention. Unless otherwise specified, the measurements are carried out at an ambient temperature of 25 °C, an ambient air pressure of 100 kPa (0.986 atm), and a relative air humidity of 65%. Unless otherwise specified, the error margin of the measurement method is ±5%.

[0446] In the following test methods, when referring to PET, it should be understood that the specific test method can be applied to any polyester without adjusting the test method.

[0447] Bulk Density of the Raw Materials

[0448] When the raw material comprises a plurality of fragments, the bulk density p of the raw material BULK，FEED is calculated according to Standard ASTM D1895-17 B. The bulk density of the raw material is measured before the raw material is contacted with the first amount of the first organic compound. This method is described by taking the raw material of PET flakes as an example.

[0449] Volume range V 1 and V 2 bulk density of the first polyester

[0450] If the first polyester is in the form of a plurality of fragments, the volume segment V 1 and the bulk density of the first polyester in the first region of the volume segment V 2 are determined as described below. This method is illustrated by taking PET flakes as an example.

[0451] a. Assume that the bulk density of the PET flakes leaving the volume segment V 1 is the same as the bulk density p 1 of the flakes in the volume segment V BULK,V1 . The value of p BULK,V1 is determined by taking 10 samples of PET flakes at the outlet of the volume segment V 1 and calculating p BULK,V1 using the same procedure as for calculating the bulk density of the raw material.

[0452] b. Due to the pressure in the first region of the volume segment V 2 , the PET flakes will be compressed, resulting in an increase in the bulk density p BULK,V2,Z1 in the first region. The bulk density is calculated as follows:

[0453] p BULK,V2,Z1 = C FACTOR × p BULK,V1 ,

[0454] where C FACTOR is the compression coefficient.

[0455] c. The bulk density p 2 of the PET flakes in another region of the volume segment V BULK,V2,Z2 is determined by taking 10 samples of PET flakes at the outlet of the volume segment V 2 and calculating p BULK,V2,Z2 using the same procedure as for calculating the bulk density of the raw material.

[0456] The compression coefficient C FACTOR is determined as follows:

[0457] a. The head pressure p 2 at the bottom of the volume segment V HEAD,V2 is calculated as follows:

[0458] p HEAD,V2 = [H MEG,V2 × (p PET - p MEG ) + (H REACTOR,V2 – H MEG,V2 ) × p BULK,V2,Z2 × a GRAV ,

[0459] wherein, H MEG,V2 is the height of the first organic compound (e.g., MEG) in the volume segment V 2 (measured from the bottom of the volume segment V 2 ), H REACTOR,V2 is the height of the volume segment V 2 , p PET is the density of PET (SI unit system) (1380 kg / m 3 ), p MEG is the density of MEG (SI unit system) (1110 kg / m 3 ), p BULK,V2,Z2 is the SI unit system, a GRAV is the acceleration due to gravity (9.81 m / s). The value of p HEAD,V2 is in units of N / m 2 .

[0460] b. Place a 500 ml PET sheet (V PET,C-TEST,INITIAL ) into a cylindrical container with a diameter of 50 mm. The PET sheet sample is taken from the raw material and not mixed with any organic compounds.

[0461] c. Apply pressure to the PET sheet using a cylindrical rod with a diameter of 12 mm. The pressure p ROD,TEST applied by the rod is calculated as follows:

[0462] p ROD,TEST = p HEAD,V2 × (A CONTAINER / A ROD ),

[0463] wherein, A CONTAINER is the diameter of the cylindrical container (1964 mm 2 ), A ROD is the diameter of the rod (13 mm 2 ).

[0464] d. Apply the pressure p ROD,TEST to the PET sheet in the cylindrical container for 5 minutes. Then remove the rod and measure the volume (V PET,C-TEST,AFTER ) of the PET sheet in the cylindrical container.

[0465] e. The above experiment is conducted 10 times. Compression factor C FACTOR is calculated as follows:

[0466] C FACTOR = V PET,C-TEST,INITIAL,AVG – V PET,C-TEST,AFTER,AVG ,

[0467] wherein, V PET,C-TEST,INITIAL,AVG (500 ml) is the average volume of the PET sheet in 10 repeated experiments, measured before using the rod, while V PET,C-TEST,AFTER,AVG is the average volume of the PET sheet in 10 repeated experiments, measured after removing the rod.

[0468] Mass Ratio of the First Polyester to the Organic Compound

[0469] The mass ratio of the first polyester to the organic compound is determined as described below. This method is illustrated by taking the PET sheet as the first polyester, MEG as the first organic compound, and another organic compound as examples.

[0470] For the volume segment V 1 the mass ratio of PET to MEG is determined as described below. The collective sample for determining the mass ratio is obtained as Figure 9 shown. The mass ratio is determined by first measuring the mass of the collective sample of the first initial mixture M SAMPLE,TOTAL,V1 . Then, MEG is poured out from the collective sample, and the remaining PET sheet is placed in an oven at 250 °C for 1 hour. After 1 hour, the PET sheet is taken out and weighed to obtain the mass of the PET sheet M SAMPLE,PET,V1 . Therefore, the mass of MEG in the collective sample M SAMPLE,MEG,V1 is given by

[0471] M SAMPLE,MEG,V1 = M SAMPLE,TOTAL,V1 - M SAMPLE,PET,V1 .

[0472] Then, the mass ratio of PET to MEG in the volume segment V 1 is calculated as follows:

[0473] R PET / MEG,SAMPLE,V1 = M SAMPLE,PET,V1 / M SAMPLE,MEG,V1 .

[0474] I. For the mass ratio R 2 of PET to MEG in the first region of the volume segment V PET / MEG,V2,Z1 the calculation method is as follows:

[0475] a. The calculation formula for the filling ratio V F-RATIO,PET,V2 of the sheet is as follows:

[0476] V F-RATIO,PET,V2,Z1 = pBULK,V2,Z1 / p PET ,

[0477] where p BULK,V2,Z1 is the bulk density of the flakes in the first region of volume segment V 2 , calculated as described above, and p PET is the density of PET (1380 kg / m 3 ).

[0478] b. The filling ratio V F-RATIO,MEG,V2,Z1 of MEG is calculated as follows:

[0479] V F-RATIO,MEG,V2,Z1 = 1 – V F-RATIO,PET,V2,Z1 .

[0480] c. Then calculate the ratio of the filling ratio R F-RATIOS,V2,Z1 as follows

[0481] R F-RATIOS,V2,Z1 = V F-RATIO,PET,V2,Z1 / V F-RATIO,MEG,V2,Z1 .

[0482] d. Use the following formula to calculate the mass ratio R 2 of PET to MEG in the first region of volume segment V PET / MEG,V2,Z1 :

[0483] R PET / MEG,V2,Z1 = R F-RATIOS,V2,Z1 × (p PET / p MEG ),

[0484] where p MEG is the density of MEG (1113 kg / m 3 ).

[0485] II. The mass ratio R 2 of PET to MEG in another region of volume segment V PET / MEG,V2,Z2 is calculated by taking 10 PET flake samples from volume segment V 2 . Each sample is 100 g. The PET flakes in the sample are adhered with MEG on their surfaces. The mass ratio R SAMPLE,PET / MEG of the sample is calculated as follows:

[0486] a. The mass of the sample is denoted by M SAMPLE,V2,Z2 . This mass is the sum of the mass of the PET flakes M SAMPLE,PET,V2,Z2 and the mass of the MEG adhered to the PET flakes M SAMPLE,MEG,V2,Z2 .

[0487] b. Place the sample on the tray, then place the tray in the oven and bake at 250 °C for at least 1 hour. Take out the sample every 20 minutes, weigh it with an analytical balance, and then put it back into the oven. Repeat this process until the change in the mass measurement values does not exceed 0.2% for three consecutive times. The average value of the last three measurement values is M SAMPLE,PET,V2,Z2 . The mass of MEG is determined by

[0488] M SAMPLE,MEG,V2,Z2 = M SAMPLE,V2,Z2 – M SAMPLE,PET,V2,Z2 given.

[0489] c. Therefore, the mass ratio of PET to MEG in the sample is given by

[0490] R SAMPLE,PET / MEG,V2,Z2 = M SAMPLE,PET,V2,Z2 / M SAMPLE,MEG,V2,Z2 given.

[0491] d. The mass ratio R PET / MEG,V2,Z2 is calculated as follows: the average value of the R SAMPLE,PET / MEG,V2,Z2 values calculated from 10 samples.

[0492] Property Change

[0493] The percentage change in a physical property (e.g., the intrinsic viscosity of the first polyester) is determined as follows:

[0494] χ = 100 × |P 2 – P 1 | / P 1 ,

[0495] where χ represents the percentage change, P 1 is the average value of the physical property measured at the first position, and P 2 is the average value of the physical property measured at the second position. This change can be an increase or a decrease. 10 measurements should be made at the first position, with each measurement interval of 5 minutes, where P 1 is the average value of the 10 measurements made at the first position. Similarly, 10 measurements should be made at the second position, with each measurement interval of 5 minutes, where P 2 is the average value of the 10 measurements made at the second position.

[0496] For determining the percentage change in the intrinsic viscosity and molar mass (e.g., weight-average molar mass, number-average molar mass) of the first polyester in the volume section V 1 , P 1 should be measured at the entrance where the first polyester enters the volume section V 1 , while P 1 should be measured at the exit where the first polyester leaves the volume section V 2 .

[0497] For determining the percentage change in the intrinsic viscosity and molar mass (e.g., weight-average molar mass, number-average molar mass) of the first polyester in volume segment V 2 , the change in physical properties shall be calculated using the values expressed in the units used in the description. For example, the change in temperature shall be calculated using the values expressed in 2 units. P shall be measured at the entrance where the first polyester enters volume segment V 1 , while P shall be measured at the exit where the first polyester leaves volume segment V 2 . 2 .

[0498] Unless otherwise specified, the relative proportion β of a physical property (e.g., the number of particles per unit area of at least one impurity) is determined as follows: ℃ in

[0499] Relative Proportion of Characteristics

[0500] β = P

[0501] / P 1 / P 2 ,

[0502] where P 1 is the average value of the property measured at the first position, and P 2 is the average value of the property measured at the second position. Except for the P 1 value of the raw material, the values of P 1 and P 2 are calculated as described in the method for determining the "change in property".

[0503] To determine the relative proportion of the number of particles per unit area of at least one impurity in the raw material to the number of particles per unit area of at least one impurity at the exit of volume segment V 1 , P is measured in the raw material before the raw material is fed into volume segment V 1 , while P is measured at the exit where the first polyester leaves volume segment V 1 . For the raw material, 10 measurements of P 1 are made at 10 different positions in the raw material, and these positions are evenly distributed in the volume of the raw material. 2 . 1 For the raw material, 10 measurements of P are made at 10 different positions in the raw material, and these positions are evenly distributed in the volume of the raw material.

[0504] To determine the relative proportion of the temperature in the first region of volume segment V 2 to the temperature in another region, P is measured at the entrance where the first polyester enters volume segment V 2 , while P is measured at the exit where the first polyester leaves volume segment V 1 . 2 while P is measured at the exit where the first polyester leaves volume segment V 2 .

[0505] To determine the volume segment V 2 the relative ratio of the number of particles per unit area of at least one impurity in the first region to the number of particles per unit area of at least one impurity in another region in the first polyester, measure P 2 at the inlet where the first polyester enters the volume segment V 1 and measure P 2 at the outlet where the first polyester leaves the volume segment V 2 .

[0506] The volume segment V 2 the relative ratio β of the mass ratio of the first polyester to the first organic compound in the first region to the mass ratio of the first polyester to the first organic compound in another region is calculated as follows: PET / MEG,V2,Z1 / Z2 Calculation is as follows:

[0507] β PET / MEG,V2,Z1 / Z2 = R PET / MEG,V2,Z1 / R PET / MEG,V2,Z2 ,

[0508] wherein, R PET / MEG,V2,Z1 and R PET / MEG,V2,Z2 are calculated as described above.

[0509] Values expressed in the units used for the properties in the description should be used to calculate the relative ratio. For example, values expressed in °C should be used to calculate the relative ratio of temperature.

[0510] Density of the First Polyester

[0511] The density of the first polyester is well known in the art and can be found, for example, in C.A. Harper, Modern Plastics Handbook: Handbook, McGraw-Hill Professional, New York, 2000 and https: / / en.wikipedia.org / wiki / Polyethylene_terephthalate.

[0512] Composition of the Raw Materials

[0513] Raw material C PVC the PVC content in is determined by selecting 10 samples containing PET flakes from the raw material. The selection positions of the samples should be evenly distributed in the volume of the raw material. The PVC content of sample C SAMPLE,PVC is determined as follows:

[0514] i.) Weigh out 250 g of the sample. The weighed sample is sample A with a mass of W A of the sample. Place sample A on the tray.

[0515] ii.) Bake the tray in an oven at 200 °C for 2 hours.

[0516] iii.) Remove the tray from the oven and allow sample A to cool to room temperature (25 °C or lower).

[0517] iv.) Remove any charred or blackened parts or fragments from sample A - the removed parts or fragments form sample B.

[0518] v.) Weigh sample B. The mass of sample B is W B .

[0519] vi.) The PVC content C of the sample SAMPLE,PVC is calculated as follows:

[0520] C SAMPLE,PVC = W B / W A × 10 6 ,

[0521] where C SAMPLE,PVC is the PVC content in ppm.

[0522] Weigh samples A and B using an analytical balance. The PVC content in raw material C PVC is the average of the C SAMPLE,PVC values determined for the samples.

[0523] Determine the content of floatable impurities in raw material C by selecting 10 samples containing PET flakes from the raw material. The sampling locations should be evenly distributed throughout the volume of the raw material. The content of floatable impurities in sample C F is determined as follows: SAMPLE,C i.) Pour 500 ml of distilled water into a plastic beaker.

[0524] ii.) Weigh out 250 g of the sample. The weighed raw material is sample C with a mass of W

[0525] iii.) Transfer sample C to the plastic beaker and stir the distilled water and sample C for 10 minutes. C of sample C.

[0526] iv.) Let the mixture of distilled water and sample C stand for 10 minutes.

[0527] v.) Remove any floating matter from the surface of the distilled water and place the removed material in a petri dish. Measure the mass W

[0528] of the petri dish with the removed material. D .

[0529] vi.) Place the petri dish in the oven and bake at 110 °C for 1 hour.

[0530] vii.) Take the petri dish out of the oven and place it in a desiccator to cool. Measure the mass W of the cooled petri dish. E .

[0531] viii.) The floatability content C of the sample SAMPLE,F is calculated as follows:

[0532] C SAMPLE,F = (W E – W D ) / W C × 10 6 .

[0533] Weigh the sample C and the petri dish using an analytical balance. The content of floatable impurities in the raw material C F is the average value of the C SAMPLE,F value determined for the sample.

[0534] Determine the content of solid impurities in the raw material C S by selecting 10 samples containing PET flakes from the raw material. The sampling locations should be evenly distributed throughout the volume of the raw material. The content of solid impurities in the sample C SAMPLE,S is determined as follows:

[0535] i.) Weigh out 250 g of the sample. The weighed sample is specimen F with a mass of W F .

[0536] ii.) Spread specimen F on the surface of a stainless-steel tray and place it in the tray.

[0537] iii.) Manually screen out the following types of impurities from specimen F: labels, sticky labels, bottle caps and closures, colored fragments (e.g., blue, green, red, yellow, and other colors), metals, stones, rubber, any other unrecognized materials.

[0538] iv.) Provide a petri dish with a mass of W G .

[0539] v.) Place the manually sorted impurities in the petri dish and weigh the petri dish. The mass of the petri dish containing the impurities is W H .

[0540] ix.) The solid content C SAMPLE,S is calculated as follows:

[0541] C SAMPLE,S = (W H – W G ) / W F × 10 6 .

[0542] Weigh the sample F and the petri dish using an analytical balance. The raw material C S The content of solid impurities in is the average value of the C SAMPLE,S values determined for the sample.

[0543] The wt-% of PET in the raw material (PET wt-％ ) is determined as follows:

[0544] PET wt-％ = 100% – (C PVC – C F – C S ) / 10 6 .

[0545] Percentage Related to Multiple Fragments

[0546] In many preferred embodiments and aspects of the present invention, the raw material comprises a plurality of fragments. Many of these aspects and embodiments are characterized in that "at least X wt-% of the fragments" or "X wt-% or less of the fragments" have certain geometric properties, such as a thickness greater than 1 mm. Geometric properties include the thickness, width, and length of the fragments. Here X is a variable that is calculated as follows

[0547] X = M ％ / M FRAGMENT,TOTAL ,

[0548] where M ％ is the mass of the fragments having a specific property, and M FRAGMENT,TOTAL is the mass of a selected sample among the plurality of fragments.

[0549] To determine X, 10 fragment samples are selected from uniformly distributed positions in the raw material, and each fragment weighs 250 g. Thus M FRAGMENT,TOTAL is 2.5 kg. The geometric properties (such as thickness) of each fragment are measured at 5 uniformly distributed positions on the fragment. The geometric properties are measured using a caliper. The maximum value measured is defined as the geometric property value of the fragment. For example, if the thicknesses of the fragment are measured as 1.3 mm, 1.2 mm, 1.7 mm, 1.4 mm, and 1.2 mm, then the thickness of the fragment is 1.7 mm.

[0550] Particle Size of the First Particle Material

[0551] The median particle size of the first particulate material is measured using the following particle analyzer and device: Helos / BR+Rodos+Vi-bri / L. This particle analyzer and device can be purchased from Sympatec GmbH (Germany).

[0552] Temperature

[0553] The temperature is measured using a resistance thermometer commercially available from WIKA Alexander Wiegand SE&Co.KG (Germany).

[0554] The volume segment V is measured at 10 different equally spaced positions in the first region 2 the temperature of the first region. The average value of the 10 measurements determines the temperature of the first region. The volume segment V is measured at 10 different equally spaced positions in another region 2 the temperature of the other region. The average value of the 10 measurements determines the temperature of the other region.

[0555] Molar Mass

[0556] The number-average molar mass M n is defined as

[0557] The weight-average molar mass M w is defined as

[0558] where, in the above two expressions, M i is the mass of polymer i with a chain length of L, N i is the number of polymers with a chain length of L.

[0559] The molar mass (e.g., weight-average molar mass, number-average molar mass) of the first polyester is measured using gel permeation chromatography (GPC). This method is applicable to the determination of number-average molar mass and weight-average molar mass. The method is carried out as follows:

[0560] i.) A sample of the first polyester is mixed with an eluent to produce a solution with a first polyester concentration of 3.0 mg / ml. The eluent is 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) + 0.05 M potassium trifluoroacetate (KTFAc).

[0561] ii.) The solution is kept at a temperature of 23 °C for 12 hours.

[0562] iii.) The solution is filtered using a polytetrafluoroethylene syringe filter with a nominal porosity of 1.0 μm.

[0563] iv.) Inject 50 μL of the filtrate into the detector using a PSS SECcurity 1260 autosampler. The flow rate is 1.0 mL / min. The detector used is a PSS SECcurity 1260 RI detector. To evaluate the measurement results, the software PSS-WinGPC UniChrom Version 8.33 is used. The autosampler, detector, and software can be purchased from PSS Polymer Standards Service GmbH (Germany). The column temperature is 25 °C.

[0564] To evaluate the measurement results, the measurement results must be calibrated. The calibration method is as follows:

[0565] a.) Perform a conventional calibration using narrow distribution standards made of polymethyl methacrylate (PMMA), which can reproduce the separation behavior of the gel permeation chromatography (GPC) column. Measure the PMMA using the same eluent and parameter values as described in points i.) to iv.) above.

[0566] b.) Then measure eight wide distribution standards of the first polyester (e.g., PET).

[0567] c.) Based on the known M w values of the first polyester standards, use the PMMA calibration to determine the calibration of the first polyester standards. This calibration is performed using mathematical calculations. This provides the absolute molar mass for the first polyester samples. Based on the first polyester calibration curve, the molar mass distribution and molar mass average of the first polyester samples are calculated by the strip method. In addition, the calculations are performed using a computer.

[0568] The calibration curves used for the above calibration are shown in Figure 6. Figure 6A The calibration curve of PMMA is shown, corresponding to the following data:

[0569] Vp / mL Mp / Da Standard Number Increase Deviation % 13.71 988000 PSS-ReadyCal-Kit mmkitr1-07, Red -0.32 -2.14 14.31 608000 PSS-ReadyCal-Kit mmkitr1-07, White -0.31 3.37 15.15 340000 PSS-ReadyCal-Kit mmkitr1-07, Green -0.29 3.34 16.05 202000 PSS-ReadyCal-Kit mmkitr1-07, Red -0.29 -4.15 17.33 88500 PSS-ReadyCal-Kit mmkitr1-07, White -0.28 -5.10 18.42 41400 PSS-ReadyCal-Kit mmkitr1-07, Green -0.29 -1.00 19.45 18700 PSS-ReadyCal-Kit mmkitr1-07, Red -0.3 8.83 20.41 9680 PSS-ReadyCal-Kit mmkitr1-07, White -0.32 5.04 21.35 5050 PSS-ReadyCal-Kit mmkitr1-07, Green -0.35 -2.59 22.35 2380 PSS-ReadyCal-Kit mmkitr1-07, Red -0.38 -10.24 23.35 800 PSS-ReadyCal-Kit mmkitr1-07, White -0.42 6.28

[0570] Figure 6B The measured first polyester standards are shown, where the first polyester is PET. Figure 6C The calibration curve used to determine the molar mass of the first polyester is shown. Figure 6C The curve in

[0571]

[0572]

[0573] For Figure 6A and 6C the fitting, the following calibration parameters are used:

[0574] <![CDATA Figure 6A > <![CDATA Figure 6C <!-- 40 -->]]> Parameter Value Value Substance PPMA PET Eluent HFIP + 0.05 KTFAc HFIP + 0.05 KTFAc Fitting Polynomial 3 Polynomial 3 R 1.000 1.000 Mark-Houwink K - 1.5834 mL / g Mark-Houwink alpha - -0,02914

[0575] For the Figures 6A to 6C measurements shown in Figures 6A to 6C , the following columns were used: PSS PFG, 7 μm, guard column, 8 mm x 50 mm; and two PSS PFG, 7 μm, linear M, 8 mm x 300 mm. These columns are available from PSS Polymer Standards Service GmbH (Germany).

[0576] The above method was also used to measure the molar mass (e.g., weight-average molar mass, number-average molar mass) of the first intermediate product (e.g., PET oligomer), another intermediate product (e.g., recycled PET), and the product.

[0577] Composition of the First Intermediate Mixture

[0578] The amount of free MEG in the first intermediate mixture (including, for example, PET oligomers and free MEG) was determined as follows:

[0579] i.) Preparation of periodic acid solution: Add 23 g of periodic acid to a 1000 ml volumetric flask. Dissolve the periodic acid in distilled water. The volumetric flask must be filled with distilled water to obtain 1000 ml of solution.

[0580] ii.) Preparation of 10% sulfuric acid: Add 25 ml of distilled water to a 100 ml volumetric flask. Add 10 g of 98% sulfuric acid to the volumetric flask. Cool the solution to 23 °C. Then, fill the volumetric flask with distilled water to obtain 100 ml of solution.

[0581] iii.) Preparation of 10% potassium iodide: Add 10 g of potassium iodide to a beaker. Add 90 ml of distilled water to the beaker and shake vigorously.

[0582] iv.) Standardization of 0.1 N sodium arsenite solution: Add 125 ± 0.1 mg of potassium iodate to a 300 ml conical flask. Dissolve the potassium iodate in 100 ml of distilled water at a temperature of 50 °C. Add 4 g of solid potassium iodide and 4 ml of 10% sulfuric acid (prepared in step ii) to the flask. Place the solution in a closed flask and keep it dark for 5 minutes. Then add 12 g of solid sodium bicarbonate and dilute with distilled water. Titrate the formed iodine with the arsenite solution, using starch as an indicator. Calculate the F factor:

[0583] F - factor = Initial mass (mg) of KIO 3 / 3.567 x Volume of arsenite solution consumed (ml).

[0584] v.) Preparation of starch indicator solution: Add 1 g of starch powder to a 100 ml beaker, add 10 ml of distilled water, and then add 100 ml of boiling distilled water.

[0585] vi.) Take a sample of the first intermediate mixture, finely grind the sample, and determine the initial mass of the sample based on the expected ethylene glycol content.

[0586] Ethylene Glycol Content (%) Initial Sample Mass (mg) 1 9300 5 1860 10 930 15 620 20 465 30 311 40 233 50 186

[0587] vii.) Weigh the sample accurately and transfer it to a 300 ml conical flask. Prepare a slurry with 100 ml of distilled water. Acidify the slurry with 3 drops of 10% sulfuric acid (prepared in step ii.), and then add 25 ml of periodic acid solution (prepared in step i.) using a burette. Stopper the flask loosely and let it stand at 23 °C for 30 minutes. Shake it from time to time. Then, add 10 g of solid sodium bicarbonate and 10% potassium iodide (prepared in step iii.) to the flask. Shake vigorously and immediately titrate with 0.1 N sodium arsenite solution (prepared in step iv.) until it turns light yellow. Then, add 1 ml of starch indicator solution (prepared in step v.) and continue titrating until the blue color completely disappears. The end point of the titration is marked by the disappearance of the blue color. The disappearance of the color must last for 3 minutes.

[0588] viii.) Determine the blank as described in the previous step vii.), i.e., 25 ml of periodic acid solution (prepared in step i.), that is, all the added chemicals are added as described in the previous step vii. except for the addition of the sample.

[0589] ix.) The percentage of free MEG is determined as follows:

[0590] % MEG content = [(BW – V) x F x 0.31] / E

[0591] where BW is the volume (ml) of 0.1 N sodium arsenite solution consumed in the blank experiment, V is the volume (ml) of 0.1 N sodium arsenite solution consumed in the sample experiment, F is the factor of the 0.1 N sodium arsenite solution, and E is the initial mass of the sample (in g).

[0592] Mass Ratio of the First Particle Material to the First Intermediate Mixture

[0593] The mass ratio R of the first particulate material to the first intermediate mixture PM / FIM The calculation formula is

[0594] R PM / FIM = M PM / M FIM ,

[0595] where M PM is the mass of the first particulate material, and M FIM is the mass of the first intermediate mixture.

[0596] Intrinsic Viscosity

[0597] The intrinsic viscosity IV of the first polyester is measured according to standard ASTM D4603:2018, with the following changes: the flow time of the solution in the capillary viscometer is determined at 25 °C instead of 30 °C (as given in the standard).

[0598] The above method is also used to measure the intrinsic viscosity of the first intermediate, another intermediate, and the product.

[0599] Unless otherwise stated, the intrinsic viscosity of the first polyester in volume segment V 1 is measured at the outlet where the first polyester exits volume segment V 1 . Unless otherwise stated, the intrinsic viscosity of the first polyester in another region of volume segment V 2 is measured at the outlet where the first polyester exits volume segment V 2 . The intrinsic viscosity of the first intermediate is measured at the outlet where the first intermediate exits volume segment V 3 .

[0600] Number of Particles per Unit Area of At Least One Impurity

[0601] Select 10 fragments of the first polyester (e.g., 10 PET sheets). Take scanning electron microscope (SEM) images of each fragment, with an image area of 100 μm x 100 μm (see Figure 7 ). Calculate the number of impurities in each image to obtain the number of particles per square centimeter N i in each image. Here, the subscript i refers to the number of particles per square centimeter determined for the i-th fragment. Additionally, the number of impurities is calculated on the surface of the fragment, not at the edges. The number of particles per unit area P COUNT is determined as follows:

[0602]

[0603] where i = from 1 to 10. Thus, the number of particles per unit area is determined by taking the average of the values determined for 10 images.

[0604] For the raw material, fragments for determining the number of particles per unit area of the raw material are selected before the raw material is contacted with the first amount of the first organic compound.

[0605] If volume segment V 2 has a first region and another region: Fragments for determining the number of particles per unit area in the first region are selected at the inlet where the fragments enter volume segment V 2 (i.e., the first type of inlet). Select 10 fragments every 5 minutes until 10 fragments are selected.

[0606] At the outlet where the fragments exit volume segment V2 At the outlet, debris is selected to determine the number of particles per unit area in another region. Similar to the debris selected to enter the volume segment V 2 , 10 pieces of debris are selected every 5 minutes until 10 pieces of debris are selected completely.

[0607] Pressure

[0608] The pressure is measured using a pressure gauge commercially available from WIKA Alexander Wiegand SE & Co. KG (Germany).

[0609] Residence Time

[0610] The residence time T RES is determined by the following formula:

[0611] T RES = V REACTOR / F PRODUCT VOLUME RATE ,

[0612] where V REACTOR is the volume of the volume space, such as the reactor volume, and F PRODUCT VOLUME RATE is the volume rate of the mixture (e.g., the first intermediate mixture, another intermediate mixture) leaving the volume segment.

[0613] Color Coordinates

[0614] The color coordinates of, for example, the first intermediate mixture and the product (e.g., yarn) are measured using an UltraScan VIS spectrophotometer commercially available from Hunter Lab (USA).

[0615] When the temperature of the sample is in the range of 22 °C to 25 °C, the color coordinates of the sample of, for example, the first intermediate mixture (e.g., containing PET oligomers and MEG) or the product are measured.

[0616] Properties of the First Particle Material

[0617] The properties of the first particulate material, such as the total pore surface area, total pore volume, average pore diameter, median pore diameter, mode pore diameter, and total pore volume, are all measured using mercury (Hg) porosimetry. The mercury porosimetry analysis is carried out according to ISO15901 - 1(2005). Using a filling volume of 460.82 mm 3The blank of / g calibrated the Thermo Fisher Scientific PASCAL 140 (low pressure up to 4 bar) and PASCAL 440 (high pressure up to 4000 bar), as well as the SOLID software version 3.0.2 (both provided by Thermo Fisher Scientific, Inc.). During the measurement, the pressure was continuously increased or decreased and automatically controlled by the instrument operating in PASCAL mode. The intrusion speed was set to 3 and the extrusion speed was set to 7. The "cylinder and flat plate" model was used for evaluation, and the density of Hg was corrected according to the actual temperature. The surface tension value of Hg was 0.48 N / m and the contact angle was 140°. The sample size of the first particulate material was between 0.28 g and 0.29 g.

[0618] The present invention will now be illustrated by non-limiting examples and exemplary embodiments. In the examples and figures, the following abbreviations are used: polyethylene terephthalate (PET), monoethylene glycol (MEG), bis(2-hydroxyethyl) terephthalate (BHET).

[0619] Drawings

[0620] List of Drawings

[0621] The accompanying drawings are used to illustrate the present invention and should not be construed as limiting the present invention. In addition, the drawings are not drawn to scale.

[0622] Figures 1A to 1C : Schematic diagram of the apparatus and method according to the present invention for producing a first intermediate product and another polyester.

[0623] Figure 2A and Figure 2B : Schematic diagram of the angle between another direction and the horizontal plane.

[0624] Figure 3 : Flow chart showing the steps of an embodiment of the method according to the present invention for producing a first intermediate product.

[0625] Figure 4 : Flow chart showing the steps of an embodiment of the method according to the present invention for producing another intermediate product.

[0626] Figure 5A and Figure 5B : Orientation of the direction relative to gravity.

[0627] Figures 6A to 6C : Calibration graph used in the method for measuring molar mass.

[0628] Figure 7: Scanning electron microscope image of a PET sheet, showing impurities on the surface of the PET sheet.

[0629] Figure 8 : Chart showing the pore size distribution of the first particulate material.

[0630] Figure 9 : Determining volume segment V 1 Description of the test method for the mass ratio of the raw material, more preferably the first polyester, to the first organic compound in Description of the Drawings

[0631] In the description of the drawings, a raw material containing PET sheets obtained by crushing PET plastic bottles is mentioned. Additionally or alternatively, the raw material may include textile fragments and / or threads obtained by crushing textiles. Therefore, in the description of the drawings, the term "PET sheet" should preferably be understood as a general term for PET sheets obtained from crushed bottles and / or textile fragments and / or threads obtained from crushed textiles.

[0632] Figure 1 is a schematic diagram of an apparatus and method for producing a first intermediate product and another polyester (e.g., PET) according to the present invention. More specifically, Figure 1 shows an apparatus and method for recycling used PET.

[0633] Figure 1A A cross-section of the first part of the apparatus as viewed from the side is shown. A raw material 101 containing PET sheets (the first polyester in the form of multiple fragments) is provided. Residual impurities (such as glue, polyvinyl chloride (PVC) labels, food preservatives, and flavorings) adhere to the surface of the PET sheets. The raw material may also contain other impurities, such as sand. The PET sheets are obtained by crushing PET plastic bottles for beverages. The raw material 101 is placed in the hopper 102. The raw material 101 is conveyed from the hopper 102 to the volume segment V 1 103. The conveyance of the raw material 101 can be carried out using, for example, a conveying screw, gravity, or a combination thereof. The volume segment V 1 103 can be, for example, a container, a tank, or a reactor (such as a washing reactor).

[0634] Liquid MEG (the first amount of the first organic compound) is added to the volume segment V through the inlet 104 1In 103, it is mixed (contacted) with the PET flakes and impurities that make up the raw material 101 to obtain a first initial mixture 105 containing PET flakes and liquid MEG. The first initial mixture 105 is stirred (the stirring device is not shown) to improve the mixing of the PET flakes and MEG. The stirring is carried out mechanically. MEG can remove the impurities on the surface of the PET flakes. This is partly because MEG is a strong solvent and its ability to remove organic pollutants is enhanced at medium temperatures. Stirring the first initial mixture 105 can also at least partly remove the glue on the surface of the PET flakes through the friction between the PET flakes.

[0635] At least a part of the impurities (for example, the cap fragments containing polyolefin) float on the surface 106 of the first initial mixture 105. These floating impurities can be removed by using, for example, skimming or filtration. The impurities are removed from the volume section V 1 103 through the outlet 123. In contrast, the PET flakes in the first initial mixture 105 sink to the bottom 107 of the volume section V 1 103.

[0636] The PET flakes and a part of the MEG in the first initial mixture 105 are conveyed to the volume section V 2 108 which is partially filled with MEG. The conveyance is carried out using a conveyance screw 109 (Archimedes screw) and a siphon (not shown) that is in fluid communication with the conveyance screw 109 and the volume section V 2 108. Other conveyance devices not shown, such as additional conveyance screws or pumps, can also be used. In addition, the volume section V 2 108 is in fluid communication with the volume section V 1 103. The volume section V 2 108 can be, for example, a container, a tank or a reactor, such as a pre-glycolysis reactor. The conveyance screw 109 is arranged such that the PET flakes conveyed to the volume section V 2 108 are conveyed along a direction 110 (another direction) that is at least partially opposite to the direction of gravity 161.

[0637] The PET flakes enter the volume section V 2 108 through an inlet of the first type 115. In Figure 1A it, the inlet of the first type 115 is an opening in the volume section V 2 108. In addition, MEG (another amount of the first organic compound) is injected into the volume section V 2 108. The first part of the MEG is injected in the form of steam through another type of inlet 116. The first part may include MEG in the form of steam, but when injected into the volume section V 2has already condensed prior to 108. Another type of inlet 116 is a nozzle that is adapted and arranged to inject MEG vapor into volume section V under pressure 2 108. Although only one another type of inlet 116 is shown, there may also be multiple another type of inlets 116. Another portion of the MEG is injected in liquid form through yet another type of inlet 117. This yet another type of inlet 117 is a nozzle that is designed and arranged to spray liquid MEG into volume section V 2 108. The PET flakes in volume section V 2 108 are partially depolymerized (reducing the weight-average molar mass) by glycolysis, thereby reducing the weight-average molar mass of the PET flakes in volume section V 2 Some of the PET flakes may be depolymerized into oligomers in volume section V 2 108.

[0638] A screw conveyor (not shown) conveys the PET flakes (and PET oligomers, if present) in volume section V 2 108 in an upward conveying direction 118. The MEG vapor entering volume section V 2 108 through another type of inlet 116 also flows in an upward direction, i.e., along the conveying direction 118. In contrast, the liquid MEG entering volume section V 2 108 through yet another type of inlet 117 flows in a downward direction, i.e., opposite to the conveying direction 118.

[0639] Volume section V 2 The liquid MEG in 108 includes the liquid MEG conveyed from volume section V 1 103, the liquid MEG injected through yet another type of inlet 117, and any condensed MEG vapor (injected through another type of inlet 116). The liquid MEG does not completely fill volume section V 2 108. Thus, the surface (or level) of the liquid MEG forms a boundary 119 that divides volume section V 2 108 into a first region 120 and another region 121. The another region 121 is located downstream of the first region 120.

[0640] The first region 120 is filled with yet another initial mixture that includes a mixture of PET flakes (and PET oligomers, if present) immersed in MEG. The another region 121 includes PET flakes and any liquid MEG adhering to the surface of the PET flakes, as well as MEG vapor. The another region 121 may also include PET oligomers.

[0641] As Figure 1A shown, the level 111 of the MEG in volume section V 1 103 is lower than the level in volume section V2 The level 113 of MEG in 108. Figure 1A It is also shown that the levels 111 and 113 of MEG are measured from the ground 114 (e.g., the floor of a recycling plant) to the liquid MEG surface in volume section V 1 103 and V 2 108. Due to the difference between the levels 111 and 113 of MEG, a part of the liquid MEG in volume section V 2 108 flows back to volume section V 1 103 through the conveying screw 109. The floatable impurities not removed in volume section V 1 103, and the floatable impurities conveyed to volume section V 2 108 (along with the conveyance of PET flakes) can thus be conveyed back to volume section V 1 103. The PET flakes (and PET oligomers, if any) with MEG adhered to the surface leave volume section V 2 108 through the outlet 122.

[0642] Figure 1B A cross-section of another part of the device as seen from the side is shown. The PET flakes (and PET oligomers, if any) flowing out through the outlet 122 are conveyed to volume section V 3 124, which is a reactor (e.g., a glycolysis reactor). Volume section V 3 124 is in fluid communication with volume section V 2 108. The PET flakes (and PET oligomers, if any) enter volume section V 3 124 via the inlet 125 and flow through volume section V 3 124 as shown by the arrow 136. Volume section V 3 124's inlet 125 is also located below the outlet 122 of volume section V 2 108. In other words, when the PET flakes (and PET oligomers, if any) are conveyed from volume section V 2 108 to volume section V 3 124, the PET flakes (and PET oligomers, if any) are conveyed at least partially in the direction of gravity.

[0643] MEG (another organic compound) is fed into volume section V 3 124 through the inlet 143. The mixing of PET with MEG (fed into volume section V 3 ) results in obtaining another initial mixture containing PET flakes (and PET oligomers, if any) and MEG. When the another initial mixture flows through volume section V 3At 124, MEG in another initial mixture causes further glycolysis of the partially depolymerized PET flakes (and PET oligomers, if present), reducing the weight average molar mass of the first polyester. A first intermediate mixture is thereby obtained. A delivery pipe 144 in fluid communication with outlet 126 is located within volume section V 3 124. The first intermediate mixture exits volume section V 3 124 through delivery pipe 144 and outlet 126 3 124. The first intermediate mixture exiting outlet 126 of volume section V

[0644] As Figure 1B shown by the arrow in 3 124, after leaving volume section V 4 124, the first intermediate mixture is conveyed to volume section V 4 127, which is in fluid communication with volume section V 3 124. Volume section V 4 127 can be, for example, a container or tank, such as a stirred tank. The first intermediate mixture enters volume section V 4 127 through inlet 128. In volume section V 4 127, the first intermediate mixture is mixed with diatomaceous earth (the first particulate material). The first intermediate mixture in volume section V 4 127 is stirred to improve the mixing of the first intermediate mixture and the diatomaceous earth.

[0645] As Figure 1B shown by the arrow in 4 127, the first intermediate mixture containing diatomaceous earth exits volume section V 4 127 and is conveyed to a vertical leaf filter 130 (filtering device), which is in fluid communication with volume section V 4Recirculate between 1 and 27 (not shown), so that each filter sheet of the leaf filter 130 is coated with diatomaceous earth. Initially, the filtrate (intermediate mixture) will be turbid. However, if each filter sheet has been sufficiently coated, the filtrate will become clear. Once the filtrate becomes clear, the intermediate mixture can leave the vertical leaf filter 130 through the outlet 132. The vertical leaf filter 130 filters out diatomaceous earth and other particulate materials (i.e., impurities) in the first intermediate mixture, as well as any PET flakes that have not been depolymerized into oligomers or BHET. The first intermediate mixture leaving the vertical leaf filter 130 through the outlet 132 contains only trace amounts of impurities and diatomaceous earth.

[0646] As Figure 1B shown by the arrow in, the first intermediate mixture flowing out of the vertical leaf filter 130 is conveyed through the outlet 132 to the volume section V 5 133 that is in fluid communication with the vertical leaf filter 130. The first intermediate mixture enters the volume section V 5 133 through the inlet 134. The volume section V 5 133 can be, for example, a container or a tank, such as a rectification tank. The volume section V 5 133 is used to determine and correct the color of the first intermediate mixture. If necessary, at least one colorant is added to the first intermediate mixture in the volume section V 5 133. If at least one colorant is added to the first intermediate mixture, the first intermediate mixture is stirred to better mix the first intermediate mixture with at least one colorant. The first intermediate mixture (possibly containing at least one colorant) leaves the volume section V 5 133 through the outlet 135.

[0647] Figure 1C A cross-section of another part of the device as seen from the side is shown. The first intermediate mixture that may contain at least one colorant is conveyed from the outlet 135 to the volume section V 6 137, which is in fluid communication with the volume section V 5 133. The first intermediate mixture enters the volume section V 6 137 through the inlet 138. Before entering the volume section V 6 137, a catalyst and a stabilizer can be added to the first intermediate mixture. The PET flakes in the raw material are obtained by crushing used PET bottles. During the production of PET for bottles, a catalyst is usually added. Therefore, the PET flakes in the raw material usually already contain a catalyst, and it may not be necessary to add a further catalyst during the recycling process. The volume section V 6137 is a pre-polymerization reactor that polymerizes the oligomers and BHET in the first intermediate mixture (increasing the weight-average molar mass of the first intermediate product) to obtain a polymer (another intermediate product). Another intermediate mixture containing the polymer (i.e., PET polymer) and MEG is thus obtained. In volume section V 6 137, up to 95% of the excess MEG evaporates under vacuum conditions. The excess MEG includes the free MEG delivered to volume section V 6 and the bound MEG released through polymerization. Another intermediate mixture leaves volume section V 6 137 through outlet 139.

[0648] As Figure 1C shown by the arrow in 6 137, the another intermediate mixture leaving volume section V 7 137 through outlet 139 is delivered to volume section V 7 140, and volume section V 6 140 is in fluid communication with volume section V 7 137. Another intermediate mixture enters volume section V 7 140 through inlet 141. Volume section V 7 140 is a polymerization reactor, such as a disk cage reactor, for further increasing the weight-average molar mass of the polymer and any remaining oligomers in another intermediate mixture (by polymerization). In addition, any remaining MEG in another intermediate mixture also evaporates under vacuum conditions in volume section V 7 140. The remaining MEG includes the free MEG delivered to volume section V 7 and the bound MEG released through polymerization. Another intermediate mixture containing another intermediate product leaves volume section V 7 140 through outlet 142. Another intermediate product (i.e., recycled PET) obtained after polymerization is completed in volume section V

[0649] 140 is in the form of a hot melt. The hot melt can be used to produce yarns (example of a product) and pellets commonly referred to as chips. The chips can be obtained by extruding and cooling the hot melt. Thus, another intermediate product is another polyester. 3 V 4 V 5 V 6 and the vertical leaf filter. This also applies to another intermediate mixture, i.e., another intermediate mixture is pumped between volume sections V 6 and V 7 45.

[0650] (Not shown in the figure): Another intermediate product can then be used to produce another product, such as yarn for textiles. For example, the other intermediate product in molten form is pumped through a spinning assembly. The spinning assembly is conceptually similar to a household showerhead. The number of holes in the spinning assembly determines the number of filaments of the yarn produced. The molten stream of the other intermediate product leaving the spinning assembly is cooled and coalesced into a single yarn. The single yarn is then wound onto a bobbin. The other intermediate product can be obtained without using the original PET. For example, before polymerization, the original PET monomers and oligomers are not mixed with the first intermediate product. For example, the original PET polymer is also not mixed with the other intermediate product.

[0651] Back to Figure 1A and Figure 1B : These figures show that when the intrinsic viscosity of the PET sheet is greater than or equal to the Y IV,1 value, the PET sheet is conveyed in a first direction at least partially opposite to the direction of gravity, while when the intrinsic viscosity of the PET sheet is less than the Y IV,2 value (where Y IV,1 and Y IV,2 represent variables, where Y IV,1 > Y IV,2 ), the PET sheet is conveyed in another direction at least partially along the direction of gravity.

[0652] As Figure 1A shown, after contacting with MEG in volume section V 1 103, the PET sheet is conveyed in direction 110 to volume section V 2 108, which direction is at least partially opposite to the direction of gravity 161. In volume section V 2 108, the PET sheet is conveyed in conveying direction 118, which conveying direction is opposite to the direction of gravity 161, that is, the average conveying direction of the PET sheet in volume section V 2 108 is upward. In the Figure 1A context, the first direction can be defined as the direction from the bottom 107 of volume section V 1 103 to the outlet 122 of volume section V 2 108. However, the foregoing should not be regarded as a general definition of the first direction. Conveying the PET (e.g., in the form of a sheet) in the first direction should generally be understood as that as long as the intrinsic viscosity of the PET fragments is greater than or equal to the value Y IV,1 , the PET fragments (e.g., in the form of a sheet) are conveyed at least partially along the direction of gravity.

[0653] As Figure 1B shown, when the PET sheet enters volume section V 3 124 through inlet 125, the PET sheet is conveyed in direction 136, which direction 136 is oriented along the direction of gravity 161. InFigure 1B In the context of Figure 1B , direction 136 defines another direction. However, the foregoing should not be regarded as a general definition of this other direction. The conveyance of PET (e.g., in the form of a sheet) along this other direction should generally be understood as the conveyance of PET fragments (e.g., in the form of a sheet) at least partially along the direction of gravity, provided that the intrinsic viscosity of the PET fragments is less than or equal to value Y IV,2 . However, once the PET is depolymerized, the PET oligomers and / or monomers can be conveyed against the direction of gravity or along the direction of gravity

[0654] Figure 2 is a schematic diagram 200 showing how to measure the angle between this further direction 210 and the horizontal plane 214. The horizontal plane 214 is perpendicular to the direction of gravity 261. This angle is measured as the minimum angle between the further direction 210 and the horizontal plane 214. This is shown in Figure 2A and Figure 2B . In these figures, the angle 262 is defined as the angle between the further direction 210 and the horizontal plane 214, rather than the angle 263

[0655] Figure 3 is a flowchart showing the steps of an embodiment of a method 300 according to the present invention for producing a first intermediate product Figure 3 . The optional steps in Figure 3 are shown in dashed boxes. A description of the method steps is given below

[0656] Step: Description:

[0657] 301: Provide a raw material containing a first polyester

[0658] 302: Optionally, contact the raw material with a first amount of a first organic compound in volume section V 1 to obtain a first initial mixture

[0659] 303: Optionally, convey the first polyester from volume section V 1 to volume section V 2

[0660] 304: Optionally, contact the first polyester with an additional amount of the first organic compound in volume section V 2

[0661] 305: Optionally, reduce the weight-average molar mass of the first polyester in volume section V 2

[0662] 306: Optionally, convey the first polyester from volume section V 2 to volume section V 3

[0663] 307: In volume section V 3 ​​​​The first polyester is contacted with another organic compound to obtain another initial mixture.

[0664] 308: In volume section V 3 The weight-average molar mass of the first polyester is reduced to obtain a first intermediate mixture, wherein the first intermediate mixture contains a first intermediate product and the other organic compound.

[0665] 309: Optionally, the first intermediate mixture is transferred from volume section V 3 to volume section V 4 .

[0666] 310: Optionally, a first particulate material is added to the first intermediate mixture in volume section V 4 .

[0667] 311: Optionally, the first intermediate mixture is transferred from volume section V 4 to a filtration device.

[0668] 312: Optionally, the filtration device is used to at least partially remove from the first intermediate mixture: the first particulate material, at least one impurity.

[0669] 313: Optionally, the first intermediate mixture is transferred from the filtration device to volume section V 5 .

[0670] 314: At least one colorant is added to the first intermediate mixture in volume section V 5 to adjust the b value of the Hunter Lab color coordinates of the first intermediate mixture such that b ≤ 0, more preferably b ≤ -1, and even more preferably b ≤ -2.

[0671] In Figure 3 one aspect of the embodiments, preferably, steps 304 and 305 are performed at least partially simultaneously. In Figure 3 one aspect of the embodiments, preferably, steps 307 and 308 are performed at least partially simultaneously.

[0672] Figure 4 is a flowchart showing the steps of an embodiment of method 400 according to the present invention for producing another intermediate product. Figure 4 The optional steps are shown in dashed boxes. A description of the method steps is given below.

[0673] Step: Description:

[0674] 401: Provide a first intermediate mixture containing a first intermediate product. The first intermediate product and the first intermediate mixture are obtained by Figure 3 the method. By transferring the first intermediate mixture from the filtration device to volume section V6 , thereby providing a first intermediate mixture in volume segment V 6 .

[0675] 402: Increase the mass average molar mass of the first intermediate product in the first intermediate mixture in volume segment V 6 to obtain another intermediate mixture containing another intermediate product. The another intermediate mixture further includes a first organic compound and another organic compound.

[0676] 403: Optionally, convey the another intermediate mixture to volume segment V 7 .

[0677] 404: Optionally, further increase the mass average molar mass of the another intermediate product in the another intermediate mixture in volume segment V 7 .

[0678] 405: Optionally, remove at least one organic compound, such as the first organic compound or the another organic compound, from the another intermediate mixture at least partially. This step can be carried out at least partially simultaneously with at least one or all of steps 402 and 404.

[0679] In Figure 4 in one aspect of the embodiment, it is preferred that step 405 is carried out at least partially simultaneously with at least one or all of steps 402 and 405. In a preferred embodiment of the present invention, according to the present invention, the method for producing another intermediate product includes steps 301 to 314 and steps 401 to 405. For example, Figure 3 the steps of Figure 4 can be combined with Figure 3 the steps of Figure 4 , where Figure 3 the steps of Figure 4 are carried out before

[0680] Figure 5 shows how to define the orientation with respect to the direction of gravity. Figure 5A shows a direction 570 that is at least partially opposite to the direction of gravity 561. The direction 570 can be decomposed into three components. The direction 570 has a component 571 parallel to the direction of gravity 561 and a component 572 perpendicular to the direction of gravity (the other component perpendicular to the direction of gravity is not shown). The direction of the component 571 is opposite to the direction of gravity.

[0681] Figure 5B shows a direction 570 that is at least partially along the direction of gravity 561. Similar to Figure 5A , the direction 570 has a component 571 parallel to the direction of gravity 561 and a component 572 perpendicular to the direction of gravity. However, similar to Figure 5AIn contrast, Figure 5B the direction of component 571 in

[0682] Figure 7 shows an SEM image of a PET sheet. Impurities on the surface of the PET sheet can be identified as white particles. Figure 7 Three impurities 781a, 781b, and 781c are marked in Figure 7 which is an example of an SEM image for determining the number of particles per unit area of the at least one impurity.

[0683] Figure 8 shows the pore size distribution of the first particulate material. As can be seen from Figure 8 the first particulate material has modes at approximately 17100 nm, 15100 nm, 12300 nm, 10600 nm, and 9300 nm. A mode is where the quantity dV / dlogD has a maximum value (local maximum or global maximum). dV is the differential volume and dlogD is the differential of the logarithm of the pore size of the first particulate material. The primary mode refers to the global maximum of dV / dlogD. The secondary mode refers to the second largest maximum of dV / dlogD. Figure 8 Also shown is the cumulative pore size of the first particulate material.

[0684] Figure 9 is a diagram of a test method for determining the mass ratio of the raw material (more preferably the first polyester) to the first organic compound in volume segment V 1 in. Figure 9 shows Figure 1A the volume segment V 1 103 of an enlarged cross-sectional view (for ease of illustration, Figure 9 the volume segment V in 1 103 has dimensions changed compared to Figure 1A the volume segment V in 1 ).

[0685] The volume segment V 1 in the first initial mixture 105 is divided into a plurality of height portions H, as shown in Figure 9 . The first height portion H1 is defined by the bottom 107 of the volume segment V 1 103 and the height A1, the second height portion H2 is defined by the heights A1 and A2, and so on. The last height portion H6 is defined by the height A5 and the surface 106 of the first initial mixture 105. Although Figure 9 shows 6 height portions H, the number of height portions is determined by the filling height of the first initial mixture 105 in the volume segment V 1 103. The height of each height portion should be 20 cm, but the last height portion defined by the surface of the first initial mixture ( Figure 9except for the height portion H6). For example, if the filling height of the first initial mixture in the volume section V 1 is 150 cm, the first initial mixture is divided into 8 height sections, where 7 height sections have a height of 20 cm and the last height section has a height of 10 cm. The height of the first height section H1 bounded by the bottom 107 is measured from the lowest point of the bottom 107.

[0686] Take 5 samples of the first initial mixture in each height section. The volume of each sample is 250 ml. Then all the samples are combined to obtain a collective sample. The mass ratio is determined using the collective sample.

[0687] If the volume section V 1 is stirred during the normal operation of the PET recycling process, samples should be taken while stirring the volume section V 1 . In this case, the 5 samples taken in the height section should be taken at the same position in the height section, and the sampling interval between two consecutive samples is two minutes. This is illustrated in Figure 9 , where the 5 samples in the height section H1 are taken at position B1 with a sampling interval of two minutes. The height section position where these five samples are taken can be any position in the height section.

[0688] If the stirring device is a physical stirring device (e.g., Figure 9 164 in), which does not allow samples to be taken below a certain height, the lowest height A at which samples can be taken without disturbing the stirring device min replaces the bottom 107 in the above procedure, i.e., the first height section is bounded by A min . Figure 9 Shows the new height portion I, which has been adjusted for the presence of the stirring device 164. Similar to the height portion H, the height of the height portion I is also 20 cm, except for the height portion I5 adjacent to the surface 106.

[0689] If the volume section V 1 is not stirred during the normal operation of the PET recycling process, the 5 samples taken in the height section should be taken at positions evenly distributed in a direction perpendicular to the height of the first initial mixture. This is shown in Figure 9 as positions C1 to C5.

[0690] Examples

[0691] The present invention is further illustrated by the following examples. The present invention is not limited to the examples.

[0692] Basic Settings

[0693] Unless otherwise specified, the basic settings described below apply to all examples.

[0694] Provide a raw material containing PET flakes. The PET flakes are obtained by processing (e.g., crushing) used PET bottles. The PET flakes are subjected to Figure 1A the method steps described in. In other words, the PET flakes are transported through volume segments V 1 and V 2 wherein the volume segment V 2 has a first region and another region. In volume segments V 1 and V 2 the PET flakes are in contact with MEG. Volume segment V 1 uses the following parameters: the mass ratio of PET to MEG ranges from 0.06 to 0.25, the temperature ranges from 60 °C to 65 °C, the pressure ranges from 98 kPa to 103 kPa, and the residence time ranges from 20 minutes to 30 minutes. Volume segment V 2 uses the following parameters: the mass ratio of PET to MEG at the inlet of volume segment V 2 is in the range of 0.3 - 0.5, the mass ratio of PET to MEG at the outlet of volume segment V 2 is in the range of 5 to 20, the temperature is in the range of 60 °C to 200 °C, the overpressure is in the range of 4 kPa to 8 kPa, and the residence time is in the range of 110 minutes to 150 minutes.

[0695] As Figure 1B shown, the PET flakes are then transported from volume segment V 2 to volume segment V 3 (glycolysis reactor). The PET flakes in volume segment V 3 are also in contact with MEG. In volume segment V 3 the glycolysis process uses the following parameters: the temperature ranges from 195 °C to 240 °C, the overpressure ranges from 0.7 kPa to 0.9 kPa, and the residence time ranges from 250 minutes to 420 minutes.

[0696] In V 3 depolymerization is carried out by glycolysis to obtain a first intermediate mixture containing BHET, PET oligomers, and free MEG. The first intermediate mixture contains 85 wt-% to 93 wt-% of the first intermediate product (BHET and PET oligomers), and the rest of the first intermediate mixture consists of free MEG and residual impurities (to be filtered out). The wt-% value is based on the total mass of the first intermediate mixture.

[0697] Also as Figure 1B shown, the intermediate product is transported from volume segment V 3 to volume segment V 4 . In volume segment V 4Stir the first intermediate mixture while adding the first particulate material to the first intermediate mixture. Volume segment V 4 has a temperature range of 165 °C to 185 °C. In volume segment V 4 the residence time ranges from 120 minutes to 240 minutes.

[0698] The first intermediate mixture, which now contains the first particulate material, is transferred from volume segment V 4 to a filtration device where the first intermediate mixture undergoes a filtration step. This filtration step also includes Figure 1B the pre - coating step described in. The temperature range of the filtration device is 165 °C to 185 °C and the pressure range of the filtration device is 250 kPa to 350 kPa

[0699] Once the filtration step is completed, the filtered first intermediate mixture is transferred to volume segment V 5 where, in volume segment V 5 a red colorant, a blue colorant, or both are added to the first intermediate mixture to adjust the color coordinates of the first intermediate mixture. These colorants are commercially available from Avient Corporation (USA).

[0700] Subsequently, the first intermediate mixture undergoes polymerization (polycondensation) in volume segment V 6 (polymerization reactor) and volume segment V 7 (disk - cage polymerization reactor) as described in Figure 1C . This results in recycled PET. Volume segment V 6 uses the following parameters: temperature range of 272 °C to 285 °C, pressure less than 3.3 kPa, residence time range of 130 minutes to 500 minutes. Volume segment V 7 uses the following parameters: temperature of 264 °C to 290 °C, pressure less than 0.32 kPa, residence time range of 40 minutes to 240 minutes.

[0701] The recycled PET is subsequently used to produce yarn. The recycled PET in molten form is pumped through a spin - pack. The spin - pack is conceptually similar to a household shower head. The number of holes in the spin - pack determines the number of filaments of the yarn produced. The molten PET stream flowing out of the spin - pack is cooled and coagulated into a single yarn. Then the single yarn is wound onto a bobbin. Hot melt adhesive can also produce PET chips by extruding and cooling the hot melt adhesive.

[0702] Example 1

[0703] Repeat this example multiple times in volume segment V 5The color coordinates of the first intermediate mixture were adjusted so that they are as shown in Table 1 below. Table 1 also shows how the color coordinates of the recycled PET chips and yarns are affected by the color coordinates of the first intermediate mixture.

[0704] For Table 1, the following applies:

[0705] a. The color coordinates are Hunter Lab color coordinates.

[0706] b. The color coordinates of the first intermediate mixture are measured ("set") after the color coordinate adjustment is completed.

[0707] c. Any colorant is added to the first intermediate mixture only in volume section V 5 After leaving volume section V 5 no further colorant is added to the first intermediate mixture. Thus, the color coordinates of the first intermediate mixture leaving volume section V 5 are the same as the color coordinates of the first intermediate mixture entering volume section V 6 for polymerization.

[0708] d. No colorant is added to the recycled PET chips and yarns.

[0709] e. The color coordinates of the yarn are the color coordinates of the yarn emerging from the spinning pack and that has been spun. The color coordinates of the yarn were also measured before the spinning finish was applied.

[0710] Table 1

[0711]

[0712] Example 2

[0713] Example 2 Multiple operations were carried out in volume section V 5 with different amounts of colorant added to the first intermediate mixture.

[0714] Table 2 shows the amounts added. The color coordinate changes in Table 2 are Hunter Lab color coordinates. The changes are defined as follows:

[0715] DL = L AFTER – L PRIOR ,

[0716] Db = b AFTER – b PRIOR ,

[0717] Da = a AFTER – a PRIOR ,

[0718] where L is measured before the colorant is addedPRIOR , b PRIOR and a PRIOR , measure L, a, and b after adding a colorant AFTER , b AFTER and a AFTER .

[0719] Table 2

[0720]

[0721] Unless otherwise stated, the “basic settings” described above apply equally to the examples below. In the tables given in the examples below, the magnitude of the technical effect is indicated by one or more “-” or “+”. The scale arranged from low to high is as follows: “------, -----, ----, ---, -, +, ++, +++, ++++, ++++++, +++++++”. The value “Ref” represents the reference value, i.e., the increase or decrease in the technical effect is relative to the “Ref” value. The value “0” represents no change relative to the reference value. When the “Ref” value is used, the scale arranged from low to high is as follows: “------, -----, ----, ---, -, Ref, +, ++, +++, ++++, +++++, +++++++”.

[0722] Example 3

[0723] Repeat the example multiple times, and in volume segment V 5 , the color coordinates of the first intermediate mixture were adjusted to have the color coordinates shown in Table 3. Table 3 also shows how the color coordinates of the recycled PET chips and yarns are affected by the color coordinates of the first intermediate mixture.

[0724] For Table 3, the following applies:

[0725] a. The color coordinates are Hunter Lab color coordinates.

[0726] b. The color coordinates of the first intermediate mixture are measured after the color coordinate adjustment is completed (“settings”).

[0727] c. Any colorant is added to the first intermediate mixture only in volume segment V 5 . After leaving volume segment V 5 , no more colorant is added to the first intermediate mixture. Therefore, the color coordinates of the first intermediate mixture leaving volume segment V 5 are the same as those of the first intermediate mixture entering volume segment V 6 for polymerization.

[0728] d. No colorant is added to the recycled PET chips and yarns.

[0729] e. The color coordinates of the yarn are those of the yarn that has emerged from the spinning pack and has been spun. The color coordinates of the yarn were also measured before applying the spinning finish.

[0730] Table 3

[0731]

[0732] Example 4

[0733] Volume segment V 1 Using the following parameters: the temperature range is from 70 °C to 75 °C. The example was repeated several times, volume segment V 1 The mass ratio of PET to MEG in is as shown in Table 4 below. The magnitude of the technical effect shown in Table 4 (using one or more "-" and "+") is not based on the same ratio used in Table 1. In addition, the magnitude of the technical effect is relative to Example 4.2 as a reference example.

[0734] Table 4

[0735]

[0736] The technical effects described in Table 4 are as follows:

[0737] · Degradation of PET oligomers: The amount of degradation of the oligomers that undergo degradation. This degradation leads to the formation of undesirable by-products such as diethylene glycol. A low amount of oligomer degradation is desired.

[0738] · Normal operating time of the recycling plant: The time during which the recycling plant can operate continuously without the need for downtime for maintenance. An increase in normal operating time is desired.

[0739] · Color quality of the recycled PET: It is desired that the recycled PET melt obtained after polymerization has the following HunterLab color coordinates: the L value is at least 55, and the b value is in the range of 2 to 4. Although colorants can be used to improve the color coordinates of the PET fluid, a reduction in the amount of colorant used is desired. Note that if the color quality of the PET fluid is poor, it is generally not possible to improve the color by adding colorants.

[0740] List of Reference Marks

[0741] 100 Apparatus and method for producing another polyester

[0742] 101 Raw materials

[0743] 102 Hopper

[0744] 103 Volume segment V 1

[0745] Volume section V of 104 1 entrance

[0746] First initial mixture of 105

[0747] Surface of the first initial mixture of 106

[0748] Volume section V of 107 1 bottom

[0749] Volume section V of 108 2

[0750] Conveyor screw of 109

[0751] Another direction of 110

[0752] Horizontal plane H of the first organic compound of 111 1

[0753] Volume section V of 112 2 bottom

[0754] Horizontal plane H of the first organic compound of 113 2

[0755] Ground of 114

[0756] Volume section V of 115 2 Entrance of the first type of

[0757] Volume section V of 116 2 Entrance of another type of

[0758] Volume section V of 117 2 Entrance of another type of

[0759] Conveyor direction of 118

[0760] Boundary of 119

[0761] First area of 120

[0762] Another area of 121

[0763] Volume section V of 122 2 exit

[0764] Volume section V of 123 1 exit

[0765] Volume section V of 124 3

[0766] Volume section V of 125 3 entrance

[0767] Volume section V of 1263 Outlet

[0768] Volume section V of 127 4

[0769] Volume section V of 128 4 Inlet

[0770] Volume section V of 129 4 Outlet

[0771] Vertical vane filter of 130

[0772] Inlet of vertical vane filter of 131

[0773] Outlet of vertical vane filter of 132

[0774] Volume section V of 133 5

[0775] Volume section V of 134 5 Inlet

[0776] Volume section V of 135 5 Outlet

[0777] Flow through volume section V of 136 3 Flow direction

[0778] Volume section V of 137 6

[0779] Volume section V of 138 6 Inlet

[0780] Volume section V of 139 6 Outlet

[0781] Volume section V of 140 7

[0782] Volume section V of 141 7 Inlet

[0783] Volume section V of 142 7 Outlet

[0784] Volume section V of 143 3 Inlet

[0785] Delivery pipe

[0786] Gravity direction of 161

[0787] Measured angle between another direction and the horizontal plane of 200

[0788] Another direction of 210

[0789] 214 Horizontal plane

[0790] 261 Direction of gravity

[0791] 262 Angle of orientation defining another direction relative to the horizontal plane

[0792] 263 Incorrect angle

[0793] 500 Orientation of direction

[0794] 561 Direction of gravity

[0795] 570 Direction

[0796] 571 Component parallel to gravity

[0797] 572 Component perpendicular to gravity

[0798] 700 SEM image for determining the number of impurity particles per unit area

[0799] 781 Impurity

Claims

1. A method for producing a first intermediate product, comprising the following steps a. Providing a raw material containing a first polyester; b. contacting the first polyester with another organic compound, preferably in volume section V 3 to obtain another initial mixture; c. Reduce the weight-average molar mass of the first polyester, preferably in the volume section V 3 to obtain a first intermediate mixture, wherein, the first intermediate mixture comprises: i. A first intermediate product, ii. The other organic compound; d. Adjustment, preferably in volume range V 5 of the b value of the Hunter Lab color coordinates of the first intermediate mixture; wherein, Adjusting the b value of the Hunter Lab color coordinates of the first intermediate mixture such that b ≤ 0.

2. The method according to claim 1, further comprising adjusting, preferably in volume segment V 5 the L value of the Hunter Lab color coordinates of the first intermediate mixture therein such that L≥65.

3. The method according to any one of the preceding claims, wherein, By adding at least one colorant to the first intermediate mixture, preferably in volume segment V 5 the Hunter Lab color coordinates L, b or both are adjusted.

4. The method according to claim 3, wherein, The amount of the at least one colorant added to the first intermediate mixture is determined by at least one or all of the following: a. Adding less than 200 ppm wt of a red colorant; b. Adding less than 300 ppm wt of a blue colorant; c. Adding the red colorant and the blue colorant, wherein the ratio of the red colorant to the blue colorant is in the range of 0.1 to 10.

0.

5. The method according to any one of claims 3 to 4, wherein, The at least one colorant is selected from dyes, toners, pigments, and combinations of at least two of them.

6. The method according to any one of the preceding claims, wherein, The first polyester is selected from polyethylene terephthalate, polybutylene terephthalate, polylactic acid, polypropylene terephthalate, polyethylene naphthalate, polycarbonate, polyester carbonate, polyarylate, polyester resin, and combinations of two or more of them.

7. The method according to any one of the preceding claims, wherein, The first organic compound has at least one or all of the following characteristics: a. Containing at least two hydroxyl groups; b. A molar mass of at least 60 g / mol; c. A boiling point of at least 192 °C.

8. The method according to any one of the preceding claims, wherein, At least 40 wt-% of the first intermediate product is in the form of an oligomer having 2 to 35 repeating units.

9. The method according to any one of the preceding claims, wherein, The first intermediate product has at least one or all of the following characteristics: a. An intrinsic viscosity in the range of 0.010 dL / g to 0.120 dL / g; b. A weight-average molar mass in the range of 350 Da to 800 Da.

10. A method for producing another intermediate product, comprising the following steps: a. Providing a first intermediate mixture containing a first intermediate product, wherein the first intermediate product can be obtained by the method according to any one of claims 1 to 9; b. Increasing the mass-average molar mass of the first intermediate product in the first intermediate mixture to obtain another intermediate mixture containing another intermediate product.

11. A first intermediate product obtainable by the method according to any one of claims 1 to 9.

12. Another intermediate product obtainable by the method according to claim 10.

13. A product comprising the other intermediate product according to claim 12.

14. Use of the first intermediate product according to claim 11 for producing another intermediate product.

15. Use of the other intermediate product according to claim 12 for producing a product.

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